The Sony Xperia Z1,\u00a0the latest flagship Android smartphone from Sony Mobile, has just been announced at IFA 2013. As you might expect, Pocket-lint spent an afternoon with the new handset ahead of the official launch, to see just how much has changed from its forebear, the Xperia Z."The best of Sony is about to get even better," explained Calum MacDougall, director of Xperia marketing for Sony Mobile Communications, to Pocket-lint before revealing Sony's hottest smartphone yet.Having told us that the Sony Xperia Z was the best phone Sony had ever made back in December ahead of the January CES reveal, MacDougall told us that this phone is better, and rightly so. The processor has been enhanced, the display is better, the camera is upgraded, even the bodywork has seen an improvement.When Sony say that the Z1 is better, it isn't lying. Most positively, the Xperia Z1 builds on a device that already has a lot going for it, adding some of the great features seen on the larger Sony Xperia Z Ultra, to make a very compelling smartphone.PowerFor those who like to number crunch, inside you get the new 2.2GHz quad-core Qualcomm Snapdragon 800 processor and 2GB RAM along with 16GB of storage, expandable via microSD. There's a beefy 3000mAh battery powering everything which should be enough to power you through a full day of heavy use.The Xperia Z1 will launch with Android 4.2.2 and Sony's tweaks as seen on the Xperia Z, offering you a user experience that's slighty, but not too far, removed from it's Android core. There are plenty of clever features, such as Sony's battery management options, as well as those bunlded Sony apps and services you may or may not want. Sony told us that the Xperia Z1 will get Android 4.3 as soon as possible, but hasn't put a firm date on it. We saw the device before Android 4.4 KitKat was announced.Beyond those basic specs there is NFC, GPS, Bluetooth, and all the usual things you would expect.\u00a0But it's not just about giving the new Xperia flagship a speed boost. A lot of other things have changed too.BuildOutside the design has been refined, evolving the distinctive and high-quality finish of the Xperia Z. The phone still features a large 5-inch display but Sony has worked hard, according to the head of the Sony Mobile design department, to make it a lot "friendlier" in the hand. The hard edges have gone in favour of a smoother rounded finish.The back plate is still made from glass, but the surrounding frame is now one piece, hewn from a single piece of metal, anodised to be either white, black or purple, blasted again to create an even softer edge and then anodised once again on top of that.It leaves a finished product that is two-tone in colour, but beautiful to touch - something you quite didn't get with the Xperia Z because the middle inlay was plastic. This single piece of metal also doubles as the phone's antenna.There is still plastic, but it's a thin bezel that sits on the metal to hold the screen in place, and that's all. It sits uncomfortably in what is an otherwise full metal glass affair and something even the designer says he isn't fully happy with.Waterproofing refinedSony has listened to customer feedback and cleverly ditched some of the cumbersome protective flaps that were criticised on the Xperia Z. The headphone socket is now uncovered and yet it is still waterproof, as we saw on the Xperia Z Ultra. Sony doesn't say how it is able to achieve this, but we've seen similar from the likes of the Samung Galaxy S4 Active.The end result for customers is that you don't have to worry about a flap every time you want to put your headphones on, which is a really positive change.Another bugbear that's gone from the new Z1 over the Xperia Z is the flap for the power socket. Sony has gone for a magnetic power option that means you can drop it on a docking station and get charging from there. It's a step short from going wireless for charging, but it is still welcomed.There are still flaps though. One for the hot-swappable microSD card, the SIM tray and a micro USB socket.DisplayThe Sony Xperia Z's display was very nice indeed and here the same can be said again. Sony has enhanced and improved the offering taking on board new technologies its television division have learnt over the past 12 months.The display now adds Sony's Triluminos display technology from Bravia, alongside its proprietary X-Reality engine tech. In simple non-marketing words, it promises a wider gamut of colours that helps make skin tones more natural and blues, greens and reds punchier. The 1080p resolution also helps, although that was also present on the previous model.In our time with the phone it's certainly noticeable, even on a rooftop on a sunny London afternoon. The colours are bright and vivid. Watching movies will be very enjoyable as will enjoying the photos you've taken with the new camera.CameraCameras on smartphones have become the battleground with the likes of Nokia boasting a 41-megapixel sensor, the integration of optical image stabilisation, HTC shooting for larger pixels and so on. Just as Sony continues to leverage the technology it has from its television division, is it also continuing to use the technology from its camera division too.Here Sony has included an Exmor RS 1\/2.3-inch 20.7-megapixel sensor, making it the highest resolution Android smartphone camera on the market. Sony has also included a G lens and Bionz processor for good measure.Put simply, it has taken the sensor found on the Sony HX50 compact camera and put it in the Xperia Z1.\u00a0The HX50 is a \u00a3290 camera, and while you lose the 30x optical zoom it is impressive that this really is a camera hidden in a phone that's 8.5mm thick.That's why, Sony tells us, in a blind test it has carried out against the iPhone 5, the SGS4, and the Lumia 1020, people chose pictures by the Z1 every time - we've not been able to test that ourselves, but it's certainly a bold claim. We were able to play with the camera, but weren't able to take away shots to further analyse but we will do so as soon as a we can.In our play with the camera, however, we found it to be quick and responsive, but hugely enhanced by some useful and fun features.\u00a0Similar to Lenses found on Windows Phone 8, Sony has added a number of modes to help you get more out of the camera.\u00a0The interesting ones are Social Live, Info-eye, Timeshift Burst, and AR Effect.Social Live allows you to live stream to Facebook for up to 10 minutes at a time and then have your friends comment on the video as you record it. As all that is happening you'll get to see how many friends are watching you, and at the end it will automatically save your streamed footage as a video for all to watch later.Time Shift Burst takes 61 shots at the press of the button, 30 frames before your press the shutter button and 30 frames after, when you're then given the chance to choose the picture you like the most.Meanwhile AR Effect automatically adds silly extras to your pictures like masks and Info-eye reads information in your pictures to get all the info you need to know about stuff around you - like reading a book jacket or a wine label.Just like Windows Phone 8 lenses, Sony says it has plenty of plans to add more in the future, and is actively working with third-party developers to make that a reality.First impressionsWe loved the Xperia Z when it arrived in January and here the Z1 ups the ante even more. It's got the latest generation of processor, it's got the highest resolution camera, an improved display, a big battery and it's waterproof. Add to that Sony's clean Android interface and this could be a very strong contender for phone of the year.Our time was restricted with the Z1, but what we've seen so far could mean this quickly becomes the best Android handset on the market.