(Pocket-lint) - Nokia has just announced the Nokia Lumia 925, its new flagship Windows Phone 8 handset, looking to bring you the best of Microsoft's mobile operating system. It arrives six months after the Nokia Lumia 920, so is there a substantial difference?

Nokia says the Lumia 925 and the Lumia 920 can co-exist, that they are different handsets which will appeal to different types of users. But is there space for a Lumia range which now offers five different market positions and a choice of two flagship models?

We've seen and played with both phones, having lived with the Lumia 920 and seen the Lumia 925 before launch and on launch day. But reading down the spec sheets, what's the difference?

1. It's all about design

It really is. The Nokia Lumia 925 offers a metal body with a polycarbonate back, bringing you a handset that's lighter, slimmer and sits more comfortably in the hand. The Nokia Lumia 925 is a much nicer device to hold.

However, in the redesign you lose wireless charging that the Lumia 920 offers. If you want Qi charging, you'll have to clip on a charging cover accessory to the Lumia 925. A cover is also the only way to bring a bright colour to the 925: it's black, white or grey only.

2. Weight watchers

In real terms, the Lumia 925 measures 129 x 70.6 x 8.5mm to the 920's 130.3 x 70.8 x 10.7mm. It's also, wait for it, 46g lighter at 139g, where the 920 was 185g. We criticised the Lumia 920 for being fat and it seems Nokia agrees, putting the Lumia 925 on a crash diet: it's 25 per cent lighter.

3. Memory loss

In the process, however, the Lumia 925 has had its internal storage halved. It now offers 16GB of internal storage, along with the standard 7GB of online SkyDrive storage. The Lumia 920 on the other hand gives you 32GB. If you want to carry lots of movies or music, it might be the 920 you go for. Interestingly, Vodafone in the UK will be offering a 32GB model. 

4. All on screen

The Nokia Lumia 925 has a 4.5-inch AMOLED display with a 1280 x 768 pixel resolution: that's 331ppi. The Nokia Lumia 920 has a 4.5-inch IPS display with a 1280 x 768 pixel resolution, again 331ppi. There's a difference in display technology here. The AMOLED offers more saturation to colours so might appear more punchy, emphasising the natural contrast of background and tiles in WP8. The Lumia 920 arguably has better viewing angles. There's also a difference in finish to the displays. The Lumia 925 is flatter, the Lumia 920 more curved. We love the vibrancy of the Lumia 925, and think the warmer look suits the operating system.

5. Camera

The Carl Zeiss PureView camera hardware is marginally different between the Nokia Lumia 925 and the 920. The 925 adds an extra lens element. This sixth element is glass and joins the five existing lens elements present in the Lumia 920. That means the 925 should technically  give you sharper results.

6. Nokia Smart Camera

Nokia Smart Camera introduces a range of clever shooting functions to the Lumia 925 camera. This shooting mode will capture 10 photos in quick succession and let you pick the best shot, create action shots, selective motion blur, remove background objects and so on. But wait, there's good news! Even though this debuts on the 925, it's coming to all other Lumia WP8 handsets in the Amber update later in 2013.

What about the Lumia 928?

That's the elephant in the corner. Launched as a Verizon-exclusive handset, the Nokia Lumia 928 is essentially the same device internally, but it has an OLED display and a Xenon flash for the camera and not even the 925 can offer that. That's something we'll be expecting from the Nokia Lumia 930.

So which to choose?

Nokia tells us it sees the 925 and the 920 differently, that they'll appeal to different users. Based on gaining 16GB of internal storage and wireless charging, we can't see who would choose the bulkier design of the Lumia 920 over the slick finish of the new Lumia 925.

The software features will level out and the experience of using both devices (or all three if you include the 928) is very much the same. The metal body and the lighter weight of the Nokia Lumia 925, however, makes it the nicer device to us.

Writing by Chris Hall.