With the One Max, HTC really should have improved the OIS to ensure its new phone stayed relevant. Instead, it removed OIS completely, leaving us with a predictable, middle-of-the-road UltraPixel camera that fails to stand out among the ever-improving competition. It's not bad at stills, especially if you're comparing it to another non-stabilized camera such as on an iPhone, but nor is it anything special. Comparing the low-light shot below with an equivalent image from the HTC One, there's barely any noticeable difference -- the HTC One's stabilization apparently didn't kick in to allow a longer shutter with reduced ISO and noise, so the One Max wasn't left at a disadvantage.

Next up, a quick comparison of a night-time shot, which shows how much further ahead the Lumia 1020 is in terms of camera technology. In this instance, the Lumia's advantage stems partly from its OIS, which allowed the shutter to stay open more than twice as long without introducing shake, but also from the impact of pixel blending, since the Lumia reduces noise by producing a 5MP still from a 41MP original -- something the Xperia Z1 can do too.

As 20MP and even 40MP sensors become more common, the act of pinch-zooming into a photograph to reframe it or show someone a particular part of a scene will become more common, and that just isn't possible with a 4MP UltraPixel image. If HTC had found room to increase the sensor size and the resolution up to 6MP or 8MP, we'd be a lot more excited about it.

One strong point of HTC's offering is its camera app, which is extremely fast and intuitive to use. Snapping off a photo feels instantaneous, and holding the shutter button shoots up to ten full-res shots per second. That speed is also apparent with the smooth HDR capture and processing, which takes two exposures and overlays them. Finally, just as on the One mini, the Max also offers the option to lock exposure and focus.

Video quality was bog-standard. The lack of OIS really hurts here, because it means that camera shake will consume a large and unfair portion of the available bit rate. This bit rate averages a healthy 2.7 MB/s (21.6 Mbps), so the resulting footage isn't awful, but you can see how it breaks down slightly in our sample video when we point it at the flowing water of the River Thames -- hand-shake coupled with the detail of the waves was too much for it. The quality of the audio recording isn't as good as on the original One, however, possibly due to the patent dispute with Nokia forcing a change of spec, and wind noise was noticeable in our recording. Finally, we wanted to test autofocus speed, but -- as you'll see from the clip -- a bug somehow prevented this from working while a video was being captured. Hopefully HTC will be able to fix this before the official launch.

Software

While the hardware alone will struggle to convince the masses, the One Max attempts to make up for it with its software, and we'd say it's a job almost well done. As the number suggests, Sense 5.5 -- based on Android 4.3 -- is essentially a beefed-up version of the UI that helped popularize the One, packing some new features as well as significant enhancements. The most obvious change is that the home screen now offers an extra line of icons both vertically and horizontally, but that's as far as it goes in terms of making use of the larger display -- there's no particular feature that enhances single-hand usage, nor is there a multi-window mode to allow true multitasking. Compared to the likes of the Vivo Xplay, Sony Xperia Z Ultra, Samsung Galaxy Note 3 and Oppo N1, we feel that with the One Max -- which is heavier than the aforementioned devices -- HTC missed a big opportunity to make its large form factor more usable or unique.

On the bright side, Sense 5.5 on the One Max gives us a sneak peek at what to expect when the One and One mini receive software updates of their own. One of the handier features is the "Do not disturb" mode, which can be toggled from the pull-down shortcuts tray to block calls and mute notifications (you can also add contacts to an exceptions list). BlinkFeed, a feature that's either loved or loathed by users, aims to please a wider audience by supporting RSS feeds (the XML links of which can be added from browsers), as well as Google+, keyword-based custom topics, multiple regions in the same feed, read later and offline reading. But if you insist, you can now simply turn off BlinkFeed with the top-left button on the home screen editor page (pinch anywhere on a home screen to toggle).

We're most impressed with the new Gallery app, which now offers a more intuitive interface for both browsing and creating video highlights. Like before, you can browse photos by automatically generated events or by albums, but now you can swipe horizontally to jump from one category to another, instead of having to pick from a drop-down menu. What's gone is the Friends category (which, to be honest, we barely used), but in return you gain a page that shows all your online HTC Shares, so that you can better manage your 250MB of storage space as well as comments, which is itself a new feature. With each HTC Share taking up about 30MB to 50MB of space, we'd still prefer a larger storage option in order to have more permanent cloud content -- it's more fun than having plain clips on the usual video sites. (As an aside, Max users will all receive 50GB of free storage space on Google Drive.)

Folks who are familiar with Sense 5 will need to get used to the new video highlights editor in Sense 5.5, but once you get the hang of it, it'll become your new time-waster. On top of the new interface that lets you preview the assembled clips without going full screen, there's now a new theme engine that can time its video transitions according to the beat of either the default theme music or your own music tracks. As a bonus, your video highlights can now go beyond the old 30-second limit if you use your own music, plus there's also an option to sort the clips in chronological order, something we needed badly in Sense 5. With these enhancements, we indulged ourselves in spending more time playing with different combinations for our video highlights.

Performance and battery life

Last but not least, you'll find several familiar apps bundled with Sense 5.5, including SenseTV to go with the One Max's infrared blaster, the self-explanatory Kid Mode, the driver-friendly Car app UI, Stocks and Polaris Office 5. What used to be Notes is now Scribble, which has lost sync capability with Evernote (apparently users prefer using Evernote's own app, anyway), but gained some themes and drawing effects.

Very little has changed in the processor department since the advent of the One, which means the One Max is very much a mid-cycle addition to the family rather than a new flagship. It sticks with the tried-and-true Snapdragon 600, which mostly retreats into the background and only very rarely provides any cause for complaint. Compared to Snapdragon 800 devices like the LG G2, Xperia Z Ultra or Galaxy Note 3, the primary difference is in the load times for games and other big applications. Even on a relatively simple game like Wordament, the One Max's load time was at least a couple of seconds longer than that on a Snapdragon 800 phone.

HTC One Max Xperia Z Ultra Galaxy Note 3 Quadrant 2.0 11,973 18,966 21,360 Vellamo 2.0 2,568 2,957 2,501 AnTuTu 4 26,059 N/A 35,788 SunSpider 1.0 (ms, lower is better) 1,173 431 1,103 GFX Bench 2.7 HD Offscreen (fps) 15 23 26 CF-Bench 29,137 31,702 24,653

Call quality and stability was fine on both EE and Vodafone networks in London. Reception strength was, if anything, slightly better than on some other devices. The One Max was able to get a reliable bar off EE LTE even in spots where our Xperia Z1 was occasionally forced to revert to HSPA+. And even with this single bar of reception, we managed 17Mbps down and 5Mbps up, which is pretty good. On Vodafone's HSPA+ network, we got 4.3Mbps down and 1.1Mbps up with a couple of bars of reception, which is on a par with other phones containing the same SIM in the same location.

As for battery life, we have something to celebrate: on an HSPA+ network, the 3,300mAh battery easily gave us enough juice for a day of heavy use. After 10.5 hours of calls, camerawork, gaming and lots of WiFi downloads, we still had 27 percent remaining. On a day of light use, with just a few calls and a bit of gaming, and with no charging overnight, the phone still had 14 percent of battery after 40 hours of use. This was partly helped by the default Power Saver setting kicking in when the battery indicator turns yellow -- this feature clocks down the CPU, reduces screen brightness, turns off vibration feedback and turns off the data connection while the screen is off. Add the 1,200mAh battery cover (shown above) and you should easily make it through two days without issue, provided you can stand lugging the thing around for that long.

Finally, on our standard looped-video rundown test, with WiFi on (but not connected) and data coming in over HSPA+, the phone lasted 12 hours and 50 minutes -- quite a feat considering the size of the screen. It's worth pointing out that the LG G2, with its Snapdragon 800 chip and a 10 percent smaller battery, managed 16 hours in the same test. Then again, it does have a significantly smaller screen. (Note: we'll update this post soon with the One Max's battery life on LTE, to allow for a cleaner comparison with the Note 3.)

Update: The HTC One Max survived 12 hours and 20 minutes on our rundown test while hooked up to EE's LTE network. That's around 30 percent longer than the Note 3.

Wrap-up

Big though it may be, the One Max is still overshadowed by our expectations. It should have taken things further than the One, but instead it merely attempts to cash in on the One's reputation by allowing HTC to claim that it has a "family" of One devices -- devices that in reality have little in common with each other beyond their superficial appearance. The One Max should have had a better, optically stabilized camera; it should have future-proofed itself with a Snapdragon 800 processor; and it should have been physically more manageable -- perhaps with a 5.5-inch touchscreen to compensate for the size of the BoomSound speakers, and definitely with a thickness of less than 10mm.

Why did none of this happen? Well, we actually put these questions to HTC -- one of the most open and friendliest manufacturers in this business -- and on some points it simply didn't have an answer. On other points, the implicit answer seemed to be that the One Max is a mid-term addition rather than a new flagship, perhaps primarily designed to cater for an Asian niche, and so it was never going to be the target of big investment. By contrast, the phone does require a big investment from the customer, given its premium price, so we can't recommend it over the Note 3 or the Z Ultra.

Then again, if the build quality issues we experienced get fixed in the retail unit, and if HTC can somehow improve the design of its Power Flip Case, the One Max should still attract a few buyers. It will especially appeal to someone, such as a frequent flyer, who wants a big screen and big battery specifically for the purpose of consuming video and music, at the expense of other requirements. If that's you, and if you can find the One Max for a decent price, it's worth taking a look.

Richard Lai and Brad Molen contributed to this review.