A SIM manager utility lets you edit contacts stored on each SIM, and, when sending SMS messages, you can easily choose which SIM to send the message from: a simple screen is appended to the SMS creation tool, which pops up after you press 'send'. Incoming SMS messages to both SIMs are brought together in the SMS inbox.
The Windows Mobile Comm Manager has been tweaked to make it easy to switch between SIMs when making outgoing voice calls. The DX900 has a version of Spb Mobile Shell, which you can run on top of the Windows Mobile user interface. This provides you with signal-strength information for both SIMs at the same time. The soft keypad for call dialling has the call button mapped to one SIM card and the end button to the other, so you can easily choose which to use.
E-TEN's habit of augmenting Windows Mobile with a vast array of extras is evidenced again with the DX900. When you first switch the device on, or after a hard reboot, you're offered the option of which extras to install. Choose them all and you have 105MB of storage memory remaining.
The extras are: Namecard Manager, which is used in conjunction with the camera to recognise business cards and send their contents to the contact manager; a backup utility; Voice Commander for voice control; Location SMS for sending an SMS message with your location in latitude and longitude as part of a text message; Satellite Data for improving the efficiency of the GPS receiver; and Easy Keyboard, a somewhat larger and more finger-friendly touch Qwerty keyboard than the standard Windows Mobile one.
We found the DX900 rather slow to respond to key presses at times. That's not a disaster, but it makes the DX900 feel less than slick on occasion.
Battery life is reasonable but not outstanding. We asked the DX900 to play music from a fully charged battery for as long as possible. It lasted 5 hours and 38 minutes. If you are a heavy Wi-Fi, 3G or GPS user, you may find you need to locate a power source for charging during the course of a typical day.
If you want a Windows Mobile device with dual SIM support, Acer's Tempo DX900 is the only available option in the UK. It does its job of handling two SIMs well, with the included applications having been suitably tweaked.
Additional editing by Charles Kloet