Importantly, the Z1 shares a key technology with the Lumia 1020 in the form of downsampling. Whereas the Lumia creates downsampled 5-megapixel still images from its 41MP sensor, the Z1 uses similar mathematical techniques to produce 8MP stills from a 20MP image. And although the sampling ratio is smaller, the impact of Sony's "pixel-binning" is immediately visible and beneficial. You lose resolution on your final image, of course, but you also lose lots of nasty image noise.

To demonstrate that this technology actually works in the Z1, let's compare the two images below, of an old bomber called the "Triple First." The top image was taken with manual settings and represents the full-res, 20.7-megapixel output from the sensor in relatively poor indoor lighting. In order to get a decent exposure, we had to bump the ISO to 400, which introduced quite a lot of noise, and -- more detrimentally -- the shutter had to stay open for 1/10th of a second -- long enough for some serious hand-shake to creep into the shot.

Next, we switched to the Z1's "Superior auto" mode, which detected the lack of ambient light and automatically activated pixel-binning to compensate, thereby lowering the output resolution to 8.3 megapixels. Although Superior auto mode is a bit hit-and-miss at the software level, since it often misunderstands what type of scene the camera is looking at, in this instance it worked a treat. It allowed the ISO to be pumped even higher, up to 800, without adding much noise. In turn, this allowed the shutter to open and close in around half the time, totally eradicating any motion blur in the image. As you can see below, the result is a better image, albeit with lower resolution. As an added bonus, the auto mode has also managed to improve white balance in this shot -- however, more generally, Superior auto mode was hit and miss with colors and exposure and definitely not something that can be relied upon in all situations.

So far, so good. But what happens if we want to keep that original 20-megapixel image? And what if we stack up the Z1 against its nemesis, the Lumia 1020? To explore this, we had to switch back to manual mode and set resolution to 20.7MP again. It's worth noting that this kills a bunch of camera options, such as HDR, scene selection and digital image stabilization -- but it was the only way to push the Z1's sensor to its limits.

The image below was taken at full resolution in slightly better lighting. The Z1's output is very encouraging, thanks primarily to Sony's fast f/2.0 G lens: the sample we have here is clear, detailed and unspoiled by noise (even though some noise is present). It's not as perfect as the Lumia shot directly beneath it, which has less noise and slightly better color balance and contrast, but the difference is arguably moderate. That's especially true since the Z1 is being put up against the full might of the Lumia's optical image stabilization, which allows it to keep its shutter open longer and therefore allow more light to hit the sensor.

Next, let's see how the Z1 and the Lumia 1020 compare when you take away the Lumia's advantage of optical image stabilization. This is actually an important test, because OIS is of little use when you're shooting a moving target. In fact, to get decent action shots with the Lumia, you have to deliberately disable OIS by selecting a shooting mode that prioritizes a high shutter speed.

Once again, the image samples weigh in the Lumia's favor. Even with OIS disabled, Nokia's handset takes less noisy action shots in low light. On the other hand, the Z1 is hardly outclassed. Its image is better exposed (read: brighter) and contains 50 percent more pixels. Sure, it's a bit noisy, but it's a passable image taken in very tricky circumstances. Moreover, when you consider shots with plentiful daylight, like the image of the docks below, the difference in quality between the two cameraphones becomes much, much less of an issue, with extra resolution being the only thing that puts the Lumia ahead.

In fact, this is pretty much how we'd sum up the difference between the still-image quality from these two rivals: the Lumia's advantage is significant, but it's also moderate enough that it can be considered rationally. Like any other spec, the Z1's camera module can be weighed up as part of a wider package of pros and cons -- it's not the best on the market, but it's probably the best camera module you can get in a skinny smartphone right now, and certainly -- as Sony's marketing claims -- it's the best camera in a waterproof smartphone. In terms of Android rivals, the Z1 is beaten only by the Galaxy S4 Zoom, which of course comes with even bigger humps than the Lumia 1020.

Ah, but wait. We can't finish this section without a look at video quality. Regrettably, if shooting video is as big a deal for you as shooting stills, then the Z1 has little to offer beyond other non-OIS Android phones. The lack of image stabilization means that a large portion of its total data rate (2.1 MB/s) is taken up with the artifacts of hand wobble. The Lumia, meanwhile, captures much richer video because it does away with this wobble and instead deploys its 2.5 MB/s data rate for the correct purpose: carrying actual detail from the scene. The clips below speak for themselves. (And special thanks to Parv and Liv for letting us exploit your beautiful wedding for phone testing purposes.)

Software

There isn't a great deal to report in this section. It's the same, neutral Sony skin that has become more familiar without ever inspiring any strong opinions. Its strength lies in getting the basics right -- such as seamlessly accessing local and cloud-stored pics from within the Album app, or providing plentiful opportunities for controlling power consumption -- without distracting too heavily from the cleanliness of stock Android. Depending on your outlook, you'd either call it "gimmick free" or "slightly dull."

Then again, there are a few new features that deserve a mention in the latest software build, based on Android 4.2.2. The first of these is a more feature-rich lock screen that lets you add up to six widgets that can be seen without needing to unlock the phone -- including things like Gmail, Google Now and Google+. The "Personalization" screen now includes the ability to customize Quick Settings that are accessed from the notifications pull-down, which means you can get faster access to the brightness slider if you want it (and we certainly do). A new menu on the app drawer (activated by a swipe from the left edge of the screen) makes it easy to organize, uninstall and search for apps. Finally, there's more control over "small apps" that you can run in re-sizable windows on top of your home screens.

Sony's increasingly coherent ecosystem is present in the form of access to its Video Unlimited and Music Unlimited storefronts, as well as PlayStation Mobile -- Sony's own app and gaming platform that is finally starting to be fleshed out with titles. It's pretty shocking that Video Unlimited still doesn't offer HD purchases or rentals, and it's also true that Spotify and other music-streaming services mean there's nothing especially compelling about Music Unlimited. However, there are more PlayStation-branded apps on the way, and the desirability of Sony's ecosystem (and the amount of effort it lavishes on the various components) will likely grow once the PS4 lands in November.

Performance and battery life

Sony Xperia Z1 Xperia Z Galaxy S 4 Quadrant 2.0 22,145 8,019 12,684 Vellamo 2.0 2,891 2,198 1,903 AnTuTu 3.2 29,377 19,876 26,143 SunSpider 1.0 (ms, lower is better) 804 1,900 772 GFX Bench Egypt 2.7 HD Offscreen (fps) N/A 13 39 CF-Bench 31,702 16,079 28,111 Battery rundown test 12:34 5:34 9:15

It was in this section that we previously came up against one of the biggest disappointments with the Xperia Z. Partly it was its Snapdragon S4 Pro processor lacked oomph compared to next-gen Snapdragon 600-equipped phones like the Samsung Galaxy S 4 and HTC One, but the bigger problem was that the Xperia Z, with its aging chip and thirsty 1080p display, consumed too much power.

Fortunately, Sony has addressed both those issues with the Z1. Starting with performance, the next-gen 2.2GHz Snapdragon 800 (with 2GB of RAM) beats the Xperia Z's Snapdragon S4 Pro in all the main benchmarks. Sony's implementation of the Snapdragon 800 -- or its lack of tuning for benchmarks -- results in scores that don't always beat the Snapdragon 600 in the Samsung Galaxy S 4 by a huge margin, particularly in the case of SunSpider and CF-Bench. They're still great scores, however, and the Xperia Z1 was impeccably fluid in day-to-day use and at least on a par with other 2013 flagships in terms of app load times and other things we tend to notice.

(Correction: there were some false values for the GS4 in the table above, which exaggerated its performance. Apologies -- these have now been fixed.)

The improvement in battery life is even greater. On a day of light to moderate usage, including some camera work, the Xperia Z1 lasted for a long day, a night and five hours of the next day before hitting the red -- at which point it still had enough juice for a few more hours. Only once did we manage to kill the battery within a day -- and that was a 17-hour day that involved a one-hour Skype call over WiFi. In our standard looped video run-down test, the Xperia Z1 lasted over 12 hours -- not as quite as long as the LG G2, which has the same processor and 3,000mAh battery capacity, but a strong result nonetheless.

You do need to be careful with the battery in order to get the most out of it. We left the "Optimized backlight" setting switched on at all times except when playing a movie, and we also kept the X-Reality enhancer off. We didn't go as far as engaging the Z1's "Stamina mode," however, since that disables cellular and WiFi data while the display is off, which would prevent push notifications -- but some users, who don't need push, could extend battery life greatly by using that option.

One thing we did have to be careful of was WiFi -- during one rundown test, we accidentally left the phone connected to a WiFi network (we normally leave WiFi on, but disconnected), and somehow we nuked the battery in four hours -- likely due to Dropbox syncing photos in the background. It seems to be heavy WiFi use that is particularly inefficient, so be careful what apps you leave running. The upshot: the phone has great stamina, but you have to get to know it a little in order to achieve consistency.

Finally a note on call quality and data speeds: as with the Xperia Z, there really are no problems to report in this area. Calls are, if anything, clearer than average through the earpiece, but there's little positive to say about calls made through the meek speakerphone. As for data, we got solid 5 Mbps downloads and 1.2 Mbps uploads over HSPA+ on Vodafone in London at an indoor location with four or five bars of reception. The phone has a capable LTE modem too, of course, which delivered over 20Mbps down and 9Mbps up on O2's London network, even indoors and with only two bars of reception.

Wrap-up

If we were being cynical, we'd say that the Xperia Z1 risks falling into the same trap as its predecessor. Sony has thrown everything it has into the new 20-megapixel camera module, and yet it hasn't managed to beat Nokia's flagship Windows Phone. The evidence is clear: the Z1 shoots noisier stills than the Lumia 1020 and its video recordings suffer immensely from the lack of optical image stabilization. That potentially compelling reason to buy the Z1 has already evaporated.

Then again, if you evaluate the Z1 on its individual merits, you can understand how the device might manage to win people over. Despite the marketing around the camera, this phone should actually be regarded as a jack-of-all-trades. To twist the phrase, the Z1 is masterful at being a jack-of-all-trades -- to the point where this well-roundedness becomes a compelling feature in its own right. The camera, the screen, the processor, the battery life, the build quality -- none of them are market-beaters on their own, but together, in one package, they make a sensible buy for anyone looking for a big-screened, high-spec Android smartphone.

Our only hesitation would be this: now that Sony is beginning to find its feet in this business, such that its technology is getting better from generation to generation, it's possible that the Z1 will be overwhelmed by a superior replacement within a year (or even six months). That is, after all, what happened to the Xperia Z. Whereas other manufacturers, like Samsung and HTC, have relatively clear and predictable release cycles, such that phone upgrades can be reliably synced to new launches, that doesn't yet apply to Sony -- so perhaps there's an argument for holding out to see what comes next.