Sony has taken its popular Xperia Z smartphone and tuned it into the Xperia Z1. In our video review of the Xperia Z1 we witness a power house upgrade to an already great Android phone. To find out more read our full review: Sony Xperia Z1 review: Xperia Z gets tuned but puts on weight.

The Xperia Z1 looks like its predecessor Xperia Z smartphone but has a more stylish and rounded aluminium design. It feels nicer in the hand but unfortunately the device is bigger, thicker and heavier than before.

The smartphone is still dust- and waterproof but the headphone jack no longer requires a flappy cover. Build quality is exemplary and although dirt still collected at the edge of the glass, the problem is significantly better and you can always wash the phone under the tap.

The Xperia Z1's weight gain is offset by some impressive hardware upgrades. RAM remains the same but the processor has been bumped to an impressive 2.2 GHz. The smartphone set records in all our benchmark tests and shows faultless performance.

Sony has keep the 5 in Full HD screen and although there's new Triluminos and X-Reality technology, the display only looks marginally better than the Xperia Z's.

Xperia Z1 review: camera

The addition of a dedicated camera button is a welcome one and the camera is one of the main selling points of the Z1. At 20.7 Mp it's the highest resolution on Android smartphone to date.

The quality of photos and video is great but it's not quite the supreme shooter which Sony makes out. By default, the Z1 strangely shoots at 8Mp with only manual mode allowing access to the full plethora of pixels.

Camera apps for burst mode, panoramas, effects are included - plus some more gimmicky ones like Info Eye which attempts to give you details on what the camera sees and an Augmented Reality mode.

Sony has done some spring cleaning with its Android user interface which looks cleaner and more stylish in parts. There are handy widgets and small apps but things get a bit messy with a few too many pre-loaded apps.

Navigation buttons take up a portion of the screen, which is a shame when there is plenty of space on the device below the screen for dedicated buttons. However, they do disappear for full screen video and the like.

Flagship smartphone typically provide a day of battery life but the Xperia Z1 lasted us double this. You'll be able to charge the phone every other night or even less if you make use of the metal contacts designed for a charging station.

The Xperia Z1 is a powerhouse upgrade to the already fantastic Z1 with an all-round impressive spec. It's unfortunate then that it's bigger and heavier than its predecessor. The Z1 is easily one of the best Android handsets around but the high price tag taints this slightly. We award four and a half stars and our recommended award.

See: What's the best phone you can buy in 2013? and Xperia Z1 vs Galaxy Note 3 comparison review.