The Acer M900 matches its brothers for connectivity options. It's a quad-band GSM handset with HSDPA 3G fast internet connection (up to 7.2Mbps), Wi-Fi (802.11b/g) and Bluetooth 2.0 with stereo A2DP. It's very well connected in other words, and we had no trouble either linking to our Wi-Fi or finding Bluetooth-enabled devices in our vicinity.
Media playback is via Windows Media Player as well as Acer's own, basic music player. Widescreen movie trailers can be scaled up to fit the width of the screen, though you'll still be left with black bars top and bottom, and there's no option to pan and scan.
Good quality video clips look great on the screen though, with a fair amount of detail in the black levels and speedy rendering.
The large speaker on the back was surprisingly quiet, though it offered a fairly clear and full sound, and didn't appear prone to distortion. Just as well since the supplied headphones sound horribly tinny and compressed, and there's no easy way to upgrade them since there's no 3.5mm jack plug. Format-wise, it can handle MP3, WMA, AAC, WAV, AMR, SP-MIDI, MIDI, MMF, AWB and RMI audio formats, with 3GP, MPEG4, WMV, H.263 and H.264 for video.
Unlike HTC's WinMo handsets, there's no preloaded Opera browser (though it's the work of a moment to download it), just Internet Explorer 6.
The resolution switches to landscape when you open the keyboard (though there's also an accelerometer on board), and you can use the jog dial to help you move around pages, as well as brushing the screen with your finger.
Zoom is via the onscreen menu however, rather than anything more immediate, which is a bit fiddly. All in all, it's not a bad browser, especially with the QWERTY keyboard for inputting URLs and data, but there's room for improvement.
The A-GPS function is supported by Google Maps and it had no trouble finding our north London location or directing us to our chosen destination.
It's accessed by a dedicated key on the front of the device and offers all the usual features including traffic updates, satellite and street view but there's no sat nav option preloaded, though this being a Windows Mobile handset, download options are available from all the big sat nav names.
The M900 comes with a full version of Microsoft Office comes on board, allowing you to read and view Word, Excel and OneNote docs, as well as view PowerPoint presentations.
There's 256MB of memory on the handset itself, which won't take you long to fill up, but this can be boosted to 8GB via the microSD card slot, though there's no card supplied.
Battery life wasn't bad for a WinMo smart phone and we just about managed two days of moderate use from a full charge, though we were careful with our use of Wi-Fi and dimmed the screen a little to stretch the charge. Still, this included phone calls, browsing, music and video playing.
The Acer M900's nearest recent rival is HTC's Touch Pro2. Both are hefty Windows Mobile touch screen devices and the M900 is 3mm longer and wider, though both devices weigh the same. Both are quad-band devices with HSDPA 3G, plus Wi-Fi, A-GPS and slide-out QWERTY keyboards.
The M900 manages an extra .2in of screen and has a 5 megapixel camera rather than 3.2 megapixels. But the Touch Pro2 has a better slide-out QWERTY keyboard – it has an extra line of keys and is easier to use. It has a better browser too, with a zoom slide for easy navigation. Also, the Pro2 has a superior battery and its processor and RAM allowance served us better than the M900's. So despite the M900's superior camera, bigger screen and lower price, we prefer the HTC Touch Pro2 because it's more satisfying to use in the long run.