Here's a conundrum: is it acceptable to release a new top-end phone just months after the last flagship if the new version is markedly better?

That's what Sony has done: just five months have passed since it launched the Xperia Z1, and yet here we are at MWC 2014 seeing the Xperia Z2 – and it's a much better handset.

If you imagine that Sony had never made the Xperia Z1, and just jumped straight here from last year's decent Xperia Z, then I'd be applauding the firm for coming in with a 5.2-inch screen that delivers great colour reproduction, tons of strong features and an ever-increasing connection to its entertainment network and accessories.
Sony Xperia Z2 review
Perhaps it's better to let the phone speak for itself. After all, this is a flagship phone that has had a huge bulk of the issues from the Z1 upgraded and improved.

I've mentioned the screen, but let's start there, as it's the element that most impressed when picking up the handset. The display is one of the most crucial parts of any phone, given you'll be spending oodles of time starting at it, and the 5.2-inch IPS LCD display here delivers a really strong performance.
Sony Xperia Z2 review
It's not just the IPS that helps (although its omission from the previous two models was horrendously obvious, creating a washed-out screen effect) but the Live Colour LED technology used on this screen really helps make everything look a lot better.

The 'trick' here is that while standard LEDs are a blue diode with a yellow phosphor on top which alters the wavelength to create white light, Sony has added in red and green elements to create a display that really pops with colour.
Sony Xperia Z2 review
Left: Xperia Z1. Right: Xperia Z2
It's claiming that this helps make everything more natural, more true to life, without being over-saturated (while it didn't mention Samsung specifically, this seems like more than a subtle dig at Super AMOLED screens which place a strong emphasis on boosting colour to the point of overdoing it in some people's eyes).

Placed side by side, the Xperia Z1 and Xperia Z2 are markedly different when viewing the same image or movie. More detail is shown in your snaps, and while Sony clearly chose the image below to show off the improved red and green performance, it is impressive how different the two are.

On top of this, you've also got Android 4.4 under the hood, making things look a lot better by removing the bars at the top and bottom of the screen to add a extra dimension on the homescreen and throughout operation - it all combines together to make a really strong and vibrant display that warrants the mountain of attention Sony will heap upon it.

The quick notifications centre has also been overhauled, bringing a much more impressive and functional feel.
Sony Xperia Z2 review
The design of the Sony Xperia Z2 is interesting – like I said, if this was compared to the Xperia Z then it would make a lot of sense, but with the Z1 in the mix it seems like Sony is really pushing the boundaries of how many flagships it can launch before consumers get annoyed..

Once again we see the huge bezels above and below the display, and the device is a few millimetres bigger as a result of adding in the larger screen.

Overall it feels a little larger than the previous iteration, but it is definitely a sleeker model that builds on the strong design language of the Xperia Z1, combining something inherently more powerful with a chassis that's much nicer to hold.
Sony Xperia Z2 review
Sony has rammed some of the best tech around into the Xperia Z2, which includes being one of the first handsets out there to use the Qualcomm Snapdragon 801 CPU – combined with 3GB of RAM it's really something under the finger.

That said, I've written that loads of times before and it's kind of redundant with today's smartphones. The speed under the finger shouldn't be any kind of an issue when you're playing with a smartphone that offers a quad-core CPU clocked at 2.3GHz and comes with that much RAM.
Sony Xperia Z2 review
Actually, there was one element that was a little slow - the camera. Both the shutter speed and the time to boot up from sleeping was rather tardy, with the latter taking around 4-5 seconds. However, given the Xperia Z1 can do the same thing in around 2 seconds, I'd wager that was down to unoptimised software rather than an inherent flaw.

Speaking of the camera: it's a great option and one that seems to be a little improved over the Z1, with the 20.7MP sensor showing great snaps and the Live Colour screen offering great colour reproduction. The difference over the predecessor appears marked, but that could be the result of a better display.
Sony Xperia Z2 review
One thing to bear in mind is that I couldn't give it a good trial in darker scenes, which is where other Sony Xperia phones have fallen apart. I'm really hoping this has been improved, as while the likes of Timeshift Video (for taking iPhone 5S-esque slo-mo video at 120fps) and Background Defocus are useful and fun new features, if the camera doesn't function as well as the likes of the HTC One in the key situations then it can't be classed as a decent one.
Sony Xperia Z2 review
There are a few features that Sony has been 'inspired by' from its competitors. These were locked away in the far reaches of the menu, but it was weird to see the likes of 'Smart Backlight Control' (also known as Samsung's Smart Stay) and the option to double tap to wake the phone (LG's Knock On) appearing.
Sony Xperia Z2 review
Sony Xperia Z2 review
These functions worked pretty well too – the double tap was particularly nifty, although not as wide-ranging as LG's offering.

There are a number of other features that Sony is using to impress with the Xperia Z2, including internal noise cancellation that even has 'Office' and 'Train' modes for those very environments.
Sony Xperia Z2 review
This would have been even more impressive if it allowed users to use any headphones, but apparently you'll need Sony's special variants if you want to get rid of some of that pesky sound out of your life.
Sony Xperia Z2 review
Given that most headphones come with a microphone now it's annoying Sony can't extend this function.

Early verdict

The Sony Xperia Z2 is a phone that can be viewed in two ways. On the one hand, it's an excellent upgrade over the Xperia Z, and features all the top end technology you could want in a very premium-feeling chassis.
On the other, it's too much like the Xperia Z1, which is only a few months old – albeit a much better version. I'm still not a fan of all that bezel above and below the screen, nor am I confident the camera will be excellent in low light.

But for a flagship phone, Sony has made a very well thought out device that ticks nearly every box you can think of, and then some.