We thought the Galaxy Note 3 was a big phone but the Lumia 1520 eclipses it. The device isn't overly thick but it's difficult to hold and use because of how wide and tall it is. The size is the main draw back and the interface being scaled means the real-estate isn't put to best use.

Keeping in trend with many Lumia smartphones, the build quality of the 1520 is excellent. Its one-piece uni-body shell feels nice in the hand; our black unit has a nice soft matt finish but other colours are glossy.

Thanks to a software update, Windows Phones have made a big leap forward in hardware. The 1520 is the first to offer a Full HD screen and quad-core processor.

The IPS screen offers exceptional viewing angles and the ClearBlack technology gives the top-notch contrast. It also performs better than most smartphones outdoors.

Improved specifications mean that, although Windows Phone has never been particularly slow, it's definitely not now. Areas such as opening large apps and multi-tasking are much smoother.

The Lumia 1520 is abundant when it comes to storage with 32GB inside, a microSD card slot and 7GB of free SkyDrive space. It's also got many of the mod-cons like 11ac Wi-Fi, NFC and wireless charging.

Nokia holds the title for best smartphone camera with the Lumia 1020, and the 1520 is no slouch either. Its 20Mp PureView main camera takes excellent photographs and videos. We just wish the various camera apps were combined into one easy to use experience.

The latest version of Windows Phone 8 adds the ability to close apps from the multi-tasking and a screen rotation lock, but the platform is still lacking a proper notification centre and a way of quickly toggling functions like Wi-Fi without delving into the settings menu.

The app situation is getting better with new arrivals to the Windows Phone Store including Vine, Instagram and Sky Go. However, it remains on a catch-up mission with iOS and Android – on apps and usability.

The Lumia 1520 is packed with a huge 12.9Wh battery but we only got, on average, a day's use. Lighter usage resulted in a couple of days but we expected more.

The Nokia Lumia 1520 has got so many things right including build quality, a great camera and a good looking screen. It's the best Windows Phone yet but software is still lacking and we just wish the device was smaller and more user friendly. We award four stars. See also: Nokia Lumia 1520 release date, price and specs UK: Confirmed.