Samsung has just announced the very first Android 2.3 Gingerbread phone, with the launch of its Nexus S. The new smartphone will be out in time for Christmas at the Carphone Warehouse and is Google's second branded handset after HTC developed the Nexus One for the search giant earlier this year. But if you've already got a Nexus One, should you be jealous? And is it worth upgrading? We take an in-depth look at the specs to see if Samsung can live up to the standards set by the Nexus name.

Winner: Nexus S
123.9 x 63 x 10.9mm; 129g
Loser: Nexus One
119 x 59.8 x 11.5mm; 130g

When it comes to mobile phones, size really does matter. No one wants an enourmous brick-like handset that's liable to make their arm ache and split the seams of their pocket. Thankfully, most of the phones around today are reasonably pocket-sized, but there's still a lot of variety. The older Nexus One is slightly shorter and narrower than the new Nexus S, although of course the S needs the extra length to accomodate its larger screen. The older handset isn't quite as slim as Samsung's new phone and although it's barely worth a mention, it's also a whole gram heavier. It swings and roundabouts when it comes to dimensions and it's likely to come down to personal preference, but we think that the Nexus S has the overall advantage in this round.

Winner: Nexus S
4-inch, 800 x 480, Super AMOLED
Loser: Nexus One
3.7-inch, 800 x 480, AMOLED

As we've already said, size is definitely important when shopping for a new smartphone and nowhere is it more noticeable than on the screen. Both handsets make use of AMOLED technology which is good news as it means that you'll get a brighter screen that uses less power and also performs well in bright sunshine. The screens also have an identical pixel count, so picture sharpness should be pretty much the same on both phones. However, the Nexus edges the win in this round thanks to its 4-inch screen, while the Nexus One's display measures a slightly smaller 3.7 inches on the diagonal.

Winner: Nexus S
1GHz Cortex A8 (Hummingbird) processor, 512MB RAM
Loser: Nexus One
1GHz Snapdragon CPU, 512MB RAM

As both of the Google handsets sport 1Ghz processors, there's not much between them. However, the Hummingbird chipset found on the Nexus S offers a strong graphics processing performance that's superior to that offered by the Snapdragon chip that powers the Nexus One. As the screen on the Nexus S is slightly bigger, it's possible that it needs a tiny bit more power from its processor, but we're confident that the Hummingbird chip can deal with that without too many problems, and that's why it takes this round.

loser: Nexus S
16GB, not expandable
winner: Nexus One
4GB, microSD expandable to 32GB

Memory size is a particularly important factor when dealing with Android handsets as you can run out of space much faster than you think. This is because, although the latest versions of Android enable you to switch apps from the phone's memory to the microSD card, most apps won't actually let you do this just yet. The Nexus S offers up an impressive 16GB of internal memory, which should be enough for all your multimedia needs, while the older Nexus One can only muster a built-in capacity of 4GB. However, it can be expanded using the microSD card slot, up to 32GB. The Samsung handset doesn't allow for expansion, so you are stuck with the (admittedly fairly capacious) 16GB.

Winner: Nexus S
5MP, flash, front facing, 720p video capture
Loser: Nexus One
5MP, flash, SD video capture

Camera and video capability on mobile phones is improving at great speed from one model to the next, so it is no surprise that the new Samsung Nexus S offers more in the imaging department than its predecessor does. Both offer a relatively standard 5-megapixel camera that can be used in low light conditions thanks to the inclusion of a flash. However, the Nexus S also has the added bonus of a front-facing camera and is also capable of HD video capture. Although the Nexus One can be using for taking video, it will only capture footage in standard definition (720 x 480). You guessed it - the Nexus S wins.

Winner: Nexus S
Android UI + Android 2.3
Loser: Nexus One
Android UI + Android 2.1 (2.3 upgrade due)

Obviously the main difference here is the OS, with the Nexus S being the very first mobile phone to boast Google's Android 2.3 (Gingerbread). According to Google, this is the fastest version of its OS so far and will include support for Near Field Communication (NFC), a new and improved keyboard with multi-touch support, internet calling, and a new user interface. However, Google has just announced that the new 2.3 update will be coming to the Nexus One by the end of 2010. Nexus One owners will be able to benefit from all the new features found on the latest OS, except for the NFC (Near Field Communication) functionality, as this is dictated by the hardware rather than the software. Once the update is out in the wild, the phones should be fairly evenly matched but that lack of NFC on the Nexus One can only mean one thing - the Nexus S takes the points.

Winner: Nexus S
Wi-Fi (802.11b/g/n), Bluetooth 3.0, DLNA
Loser: Nexus One
Wi-Fi (802.11b/g/n), Bluetooth 2.0

Once again, there's not a lot between the two handsets when it comes to connectivity, with a couple of notable exceptions. While both have Wi-Fi with the identical 802.11 b/g/n standard, the Nexus sports Bluetooth 3.0, while the Nexus One only has 2.0. Although there aren't currently many devices that are compatible with version 3.0 yet, at least the Nexus S is reasonably future-proof. The Nexus One also loses out to the Nexus S thanks to its lack of DLNA technology. This handy feature enables you to stream content between compatible devices so that you could watch videos in bed, streamed from your home server to your phone, or watch video footage on your DLNA TV that you've captured on your mobile. It might not be an important feature for everyone, but it still gives the Nexus S another win in this spec-off.

When it comes to the all-important issue of price, the new Nexus S can hardly be described as cheap. It comes free of charge on a £35 a month contract, or you'll be able to pick one up SIM free for just under £550. The Nexus One is a fair bit more affordable, with contracts starting at £30 and a SIM free handset available for around £340.

In terms of the number of rounds won, Samsung's Nexus S is the clear winner, which is no great surprise. Although the improved specs could well be enough to make current Nexus One owners jealous, it's worth noting that the new Nexus S won most of these spec-based rounds by the smallest of margins, so while it's clear that it's a slightly better phone on paper, not all of the new features will be particularly important to all Google phone users. It will also come down to personal preference when deciding between the build quality offered by Samsung and the Nexus One maker, HTC. Although it's difficult for us to make a call on this without having had a proper look at the new Nexus S, many thought that Samsung's current flagship handset - the Galaxy S - was a little on the "plasticy" side. With its heritage in Android handsets, HTC may also have the advantage when it comes to designing a Google-flavoured phone.

If you're a Nexus One owner, it certainly looks as though an upgrade to the latest Google phone might be worth your while. However, you might want to see how the Android 2.3 upgrade works out first. We'll bring you a full review of the Samsung Nexus S as soon as possible, which should help you to make up your mind.

Have you got a Nexus One? What do you think of the new Nexus S and will you be upgrading? Let us know in the comments box below.