We compare the Sony Ericsson Xperia Arc S with a rumoured Windows  Phone 7 Mango known as the Acer W4As we near the release of Windows Phone 7's Mango update, interest in the  platform is rightfully increasing. Many people are keen to see exactly what the  operating system has matured into and one device which looks set to show-off the  update's capabilities is Acer's Mango powered Acer W4.
In the interest of impartiality we've chosen to pitch the Acer W4 against a  little Android competition in the shape of Sony Ericsson's up and coming Xperia  Arc S – a device that is looking to build on the solid reputation of its  predecessor.
We're operating within the confines of speculation again this week, folks, so  do remember that what we're discussing isn't the finished, or even confirmed,  article.
PowerIf the rumours circulating can be trusted we can expect the Acer W4 to launch  with a 1GHz Qualcomm CPU and at least 512MB RAM which, although sufficient for  most tasks, isn't going to set the world alight in a market that is anxiously  awaiting its first quad-core powered smartphones.
The Sony Ericsson Xperia Arc S has a little bit more muscle though, with a  1.4GHz Scorpion CPU, Adreno 205 GPU and 512MB RAM, giving it victory in this  opening round.
Winner - Sony Ericsson Xperia Arc S
DisplayAcer's W4 looks set to include a 3.6-inch WVGA  touchscreen, which will  operate at a resolution of 480 x 800 and offer a fairly impressive pixel density  of 259ppi.
Sony Ericsson's Xperia Arc S features a 4.2-inch LED-backlit LCD screen that  operates at a resolution of 480 x 854 and offers a pixel density of 233ppi,  making it a decent choice for those that enjoy watching movies or TV shows on  their device.
There's plenty to be said for high quality, smaller screens though and we  think people will appreciate the Acer W4 irrespective of it lacking a few  millimetres in the screen department.
Winner - Draw
CameraThe Xperia Arc S offers an 8-megapixel primary camera with auto-focus, LED  flash, face & smile detection, 3D sweep panorama and Geo-tagging, making it  a pretty well rounded package for those that snap a lot of photos on the go.
The device will also feature a secondary, front-facing camera, though we  aren't sure what size yet.
The Acer W4 looks set to be outfitted with the bare minimum required of  Windows Phone 7 devices, which, of course, is a 5-megapixel sensor with  autofocus and LED flash.
There's no word yet on what other camera functionality the device will have,  or whether it will feature a secondary video-call camera.
Winner - Sony Ericsson Xperia Arc S
Operating SystemSony Ericsson's Xperia Arc S will ship  with version 2.3.4 of Google's Android OS, otherwise known as Gingerbread – a  pretty well rounded, stable and secure release of the software.
Users can also expect to find Sony  Ericsson's own TimeScape UI included too, which brings custom widgets, apps and  social networking integration along with a neat timeline driven user  interface.
Acer's W4 will launch with the newest  iteration of Microsoft's Windows Phone 7 platform, which brings a lot of new  features to the platform, such as a new unified inbox for all communications,  new and improved multi-tasking and Internet Explorer 9.
Naturally both platforms offer tons of  apps and games for download, but Windows Phone 7 has a way to go before it  catches up with Android in this respect, giving the Xperia Arc S the edge.
Winner - Sony Ericsson Xperia Arc S
Form  & BuildThere's no word on dimensions for the Acer  W4 yet, but we're expecting a device that doesn't deviate terribly from the path  set by previous Windows Phone 7 devices.
In terms of materials we're expecting  lightweight plastics and a decent build quality, but again it doesn't look  anything special.
The Sony Ericsson Xperia Arc S measures up  at 125 x 63 x 8.7 mm and weighs a modest 117g, making it a fairly  pocket-friendly smartphone.
We hope Sony Ericsson has put a little bit  more effort into the build quality of the Arc S though, as its predecessor  exuded a pound-shop feel which belied the device's underlying quality.
Winner - Draw
And there you have it. A pretty resounding  victory for the Sony Ericsson Xperia Arc S.
The device looks to be a solid addition to  the Xperia stable, and a decent upgrade on the previous device. The improved  power on offer will make the lag that afflicted the original Arc a thing of the  past.
Thankfully the specs for the Acer W4 aren't  written in stone. We might see a device that has been nipped, tweaked and  updated by the time it reaches market, and we hope that this is the case.
As it stands though, the Acer W4 is a  device that looks dated by today's standards and has little of note under the  bonnet.
Unless Acer is planning to price the device  very aggressively we can't see it making much of a splash.