If the LG G5 was just another Android rectangle, I could end this review right now with the words “buy the Galaxy S7 Edge.” LG’s riposte to Samsung is, however, more ambitious than a single phone. The G5’s intrigue stems from a set of extra accessories that plug directly into its bottom, augmenting its battery life, camera controls, and audio performance. Think of it as a Game Boy with functionality cartridges, if you will.

Modularity holds out the promise of greater versatility than a regular smartphone, and it also offers a route to upgrading and improving the G5 long after its initial purchase. In a market full of mostly cosmetic or battery-enhancing accessories, a phone that can truly be augmented with plug-in extras stands out as a tantalizing proposition.

In one important way, the G5 is already a winner for LG. This phone swept everyone up in a happy whirlwind of hype during Mobile World Congress, collecting the organizers’ prize for best new mobile device and eliciting praise from fans and critics for the boldness of its design. People, it turns out, are still in love with the idea of modular gadgets. After decades of convergence being the organizing principle of tech innovation, we’re now seeing a renewed interest in physical objects, and LG’s G5 is perfectly timed to crest that wave of nostalgia.

When I first laid eyes on the G5, it really didn’t seem like a flagship LG phone. Where were the garish design flourishes, the kooky curves, and the abundance of glossy plastic? The G5 is restrained in all the ways that LG usually isn’t, opting for a metal unibody shell with a matte finish and actually shrinking down in size from its predecessor G4. That’s what a system of powerful external accessories will do to a phone: LG has been able to streamline its new 5.3-inch device by outsourcing many of its additive features to the plug-in modules (which the company calls Friends). These extras aren’t cheap, with UK pricing for the LG Hi-Fi Plus audio module coming in at £149 , and the LG Cam Plus camera grip setting US buyers back $69. LG's most ergonomic flagship since the G2 Without consideration of its Friends, the LG G5 reminds me of a smaller Nexus 6P. It’s built out of a similar aluminum, has a similar camera bump (albeit with two cameras rather than one), and has an identically positioned fingerprint reader at the back. The G5 integrates the power button and fingerprint sensor into one, however, which has an annoying side effect: very often, I would go to press the power button to turn on the phone, but it would recognize my fingerprint first, unlock, and then immediately switch off at my actual press of the button. The major physical difference between LG’s G5 and the 5.7-inch Nexus 6P is in the width of the two devices. Single-handed use is typically a chore on the 6P and other devices in its size class (like LG’s own V10), but it’s quite comfortable on the G5. LG has improved the shape and ergonomics from the 5.5-inch G4 as well, with the new, narrower phone feeling more natural and easy to hold. The thing that LG design continues to lack, however, is refinement. The rear edge around the sides of the phone is chamfered (with a couple of unsightly breaks at the top) and weirdly sharp. That light-catching chamfer makes little sense when you consider that it has no design coherence with either of LG’s plug-in modules — it just serves to highlight the dissonance between the handset and the module jacked into it. Another sharp edge can be found at the bottom of the G5 when no Friends are connected, as the detachable "chin" of the phone doesn’t sit perfectly flush with it. I’m inclined to take some sanding paper to the whole thing to make it suitable for human use. So yes, the LG G5 is an ergonomic advancement over the G4, but it introduces its own imperfections in moving to this modular design. Refinement: others have it, LG needs it My enthusiasm for the G5’s looks was diminished by spending more time with it, but the phone partially redeems its physical compromises with the extra plug-in functionality that it’s designed to accommodate. There are two plug-in Friends at launch: a Hi-Fi Plus module for better headphone audio and a Cam Plus camera grip that synergizes with the G5’s dual-camera system. To attach either one, you have to pull off the G5’s bottom, extracting the battery in the process, move the battery to the relevant Friend, and then slot that new combo back into the phone. You have to reboot the phone each time you swap an accessory, but that usually takes no more than 15 seconds so it’s not a huge issue. A much bigger worry is the battery itself, which has a pair of hooks that attach it to either the G5’s bottom casing or the incoming Friend; I have sincere doubts that those will survive very long when subjected to a daily routine of swapping parts.

The action of swapping the Friends modules can, at its best, feel delightful. LG deliberately made the process reminiscent of swapping out a gun magazine, and when you manage to do everything right, it feels pretty seamless. But it’s the battery that causes the most friction, as most of the time you’ll be struggling to detach it, wondering if you really should be pulling with quite so much force, or reinserting it the wrong way around. The Friend modules sacrifice the G5's form in order to add more functionality As to the Friends themselves, let’s start with the 32-bit DAC (digital-to-analog converter) and amplifier contained within the Bang & Olufsen-branded Hi-Fi Plus module. It’s an upgrade over the Hi-Fi DAC contained in LG’s V10 from last year, which supported only a limited number of music apps. This new part upscales and prettifies all audio coming from the LG G5’s headphone jack, and I like what I’m hearing. Not everyone will be blown away by the difference between the G5’s integrated audio components and the Hi-Fi Plus, but once you plug in a more demanding headphone such as Audeze’s EL-8, the difference becomes easily recognizable. Where the G5 by itself sounds hollow and lifeless, the B&O module restores vitality and dynamism — this Friend can actually drive big and powerful headphones, though not to a very high volume. Overall, I like it and would make use of it, but I must reiterate my aesthetic complaint from above: the black plastic Hi-Fi Plus module looks like a pair of casual sneakers worn with the smart aluminum suit of the G5 itself. LG’s Cam Plus bumps the G5’s battery from 2,800mAh to 4,000mAh and adds a two-stage shutter key, a video recording button, and a zooming jog dial. Its stated purpose is to make single-handed photography a breeze, though it doesn’t quite live up to its aspirations. Trying to use the Cam Plus with just one hand invariably leads to issues about where to put my thumb, which gravitates toward the G5’s screen, resulting in accidental taps. The zooming dial on the Cam Plus is frictionless and has no discrete stages, so it feels unpleasant and imprecise when I’m trying to adjust it. On the positive side of things, it does switch automatically between the two rear-mounted cameras on the G5, depending on how wide I want the shot to be. LG's superb camera software makes it easy to play around with the extra camera LG has combined its excellent, optically stabilized 16-megapixel camera from last year’s G4 and V10 with a new wide-angle 8-megapixel module that allows for capturing bigger group or architecture shots. This is actually a very neat and useful system, adding functionality without sacrificing much in terms of size or performance, and it’s a strong justification for why you might want to buy a camera grip for the G5. There are a number of creative modes combining the G5’s two imaging sensors, such as embedding the 16-megapixel shot in a blurred-out frame from the 8-megapixel shooter. Just bear in mind that the second camera is lesser not just in resolution but also in quality, and its output doesn’t live up to the high standard set by the G5’s main shooter. LG’s camera system is one of the very few that I trust in all circumstances , delivering sharpness, detail, and speed that only Apple and Samsung are currently able to compete with. Editor markup for LG G5 camera sample photos. This is only visible in the story editor. I see this dual-camera system as full of creative potential, and I’d say a better designed camera grip would have made me doubly happy to explore it. As it is, though, the Cam Plus doesn’t add enough in terms of photographic ergonomics, and if I really need a physical shutter key, I can just use the G5’s volume buttons. The extra battery life might be a nice perk, but not nice enough to make me reboot the phone and put up with the huge lump attached to it. The Friends ecosystem will only grow if you believe and invest in it The key advantage of LG’s current G5 Friends is their potential forward compatibility. If people embrace LG’s modular concept and the company stays true to its promise to extend and build out the ecosystem, I can see myself buying a Hi-Fi Plus and getting repeat use from it over multiple LG flagship generations. The Cam Plus grip also doesn’t have anything that will be obviated quickly, so you might buy it once and enjoy its benefits over the course of multiple devices. But whether or not that advantage actually materializes is an open question. I don’t like how unrefined the design of these Friends is, and I’m not encouraged by the fact there are only two of them so far. The rest of LG’s Friends lineup is a series of more conventional accessories, whose claim to fame is simply an automated sync with the G5. Lost in among LG’s bravado about the G5 being the harbinger of a modular revolution is a long list of traditional smartphone strengths. The 5.3-inch display on this handset is lovely to look at and very pixel-dense with a resolution of 2560 x 1440. LG has even figured out a partial backlight to keep an always-on notification panel for those who want it. A Snapdragon 820 processor makes the G5 incredibly fast and responsive, aided by 4GB of RAM, and you can expand the integrated storage with a microSD card. Android 6.0 Marshmallow works with great fluidity here, and its power optimizations synergize with the efficient 820 chip inside to give the G5 satisfyingly long battery life . I’ve no worries about the smaller size of the battery relative to the G4, as LG’s new flagship does the typical day and a half of use with relative ease. Carrier bloatware blights the software I’m a huge fan of LG’s camera app, and I’d love to heap as much praise on the rest of the company’s user experience, but LG’s collaboration with mobile carriers really spoils things here. On AT&T in the United States, you’ll get notifications nagging you to sign up for junk, and on T-Mobile in Europe and elsewhere, you’ll get an entire folder of uninstallable crapps. Then there’s the folder of superfluous LG apps, and unrequested additions of unremovable extras like Evernote. LG is getting rid of the app tray in its new UX 5.0 software, so your best case scenario is to bundle these misfits off into an ugly corner somewhere. This is one aspect of Apple’s iOS that Android device makers really don’t need to emulate. It’s a real shame on the LG G5, in particular, because this phone has the size, performance, battery life, and camera quality for me to seriously consider it as my day-to-day device.

A big part of me hoped that the LG G5 would be an awesome phone just by itself. That its optional extras would be something I could ignore and just get on with my happy mobile life. But alas, the recurring theme with the G5 is one of almost naive design. There are reasons for why others aren’t attempting modularity, and the G5 is the perfect exhibit of them. This phone lacks the finesse and perfect fit and finish that I’ve now come to expect from most smartphones, which is the logical outcome when you have to cut more lines and holes into a phone’s metal hull to accommodate extra parts. Harmonizing the G5’s design with the plug-in accessories adds to the complexity as well, which is probably why LG didn’t even make an attempt at it. LG decided that what mattered most with the G5 was for it to be new and different and exciting — and it achieved all of those objectives. The Korean company has ably differentiated itself from its compatriot Samsung, but — and this is not the first time I’ve said this about an LG device — being different by itself isn’t enough. Samsung’s Galaxy S7 and S7 Edge aren’t actually all that different from last year’s iterations, but they deliver meaningful improvements over already strong devices and are our favorite phones of the year so far. LG is building on a strong technical platform, thanks to its great camera and performance, but the G5 is not in the same league of class and quality as Samsung’s hardware. The G5 is certainly the more interesting phone, but the S7 is the one I’d rather take home at the end of the day. I applaud LG for bringing modular phones into the mainstream limelight. I only wish the company's execution was as great as its courage and imagination. Photography by Amelia Krales

Video by Phil Esposito