The F900 runs Windows Mobile 6.1 and like most manufacturers that use this, Acer has added its own interface tweaks, called Acer Shell, over the top to make touchscreen navigation that bit easier. Acer Shell presents you with a view of a virtual desktop with various items strewn around it including an open envelope for email, a paper calendar for, you guessed it, the calendar, and a photo frame for viewing pictures.
Tapping on each item takes you to its associated app, but the problem is that not all the items are intuitive representations of the applications or menus they relate to. For example, would you really associate a jar of pens and pencils with the settings menu?
Nevertheless, the animations as you move from the icons to the actual application or menus are slick and smooth and we like the way that some of the desktop icons are dynamic. For example, the picture frame always shows the last picture you viewed in your photo album and the rollerdex shows the picture of the contact that you last called. Still, we have to admit that we much preferred the Spb Mobile Shell interface on the DX900 as it's faster and more intuitive to use.
The phone's call quality was excellent during our testing period, as the mic isn't as directional as some other handsets we've used and the earpiece is reasonably loud. The F900 comes with a sizeable 1,530mAh lithium-ion battery and on the whole battery life is par for the course for a WinMo device. We got two days from it between charges for medium usage of the key features like GPS, browsing over HSDPA and listening to music.
We don't think the F900 is quite as good a handset as the HTC Touch HD. The overall design is not as neat, the HTC TouchFlo interface is better than Acer Shell and the Touch HD feels a tad faster to use. However, the F900 is over £100 cheaper than the Touch HD and if you swapped out Acer Shell for something like Winterface or Spb Mobile Shell you'd still end up with a pretty impressive handset. So really, the choice comes down to one of price. If you've got the cash then by all means go for the Touch HD, but you're arguably getting better value for money with the F900.