Plus, all phones – smartphones, feature phones, ‘dumb’ phones – have back buttons. That’s right, the Acer DX900, a dual-SIM smartphone/PDA from computer manufacturer Acer, is missing any kind of back function.

There are a series of shortcuts within the navigation system that, if you read the 282 page manual, you’ll find out about. Otherwise, the user interface (UI) is unintuitive, and comprised of too many ambiguous icons. However, the dual-SIM function is well implemented, and it’s very easy to switch between your two numbers no matter what you’re doing. So, at least the phone succeeds at its killer app – too bad everything else suffers.

 

Look and feel

 

The DX900 is one chunky device, possibly to make room for that double SIM action. Acer’s first foray into the smartphone arena is business-oriented, packing Windows Mobile 6.1, Microsoft Exchange push email, HSDPA, Wi-Fi and GPS, plus a three-megapixel camera with LED flash as well as video and music players.

Looks wise, the device harks back to PDAs of yore, with a matt rubber casing, two call/hang up buttons and a D-pad that has an ‘OK’ button at its centre. These buttons have limited function within the navigation menu; you can only move between icons, select icons or use the hang up button to take you to the home screen.

The UI consists of two screens: a ‘Today’ menu that shows your tasks, appointments and messages, as well as which of your two SIMs are active, and the ‘Spb Shell’, a highly techie name for the slightly fresher widget homepage where you can access the time/appointment menus, plus all the other programs in the phone.

The touch-screen works well, with few lags and no missteps – however, the lack of haptic (vibrating) feedback takes some getting used to.

 

Dual-SIM business

 

The dual-SIM feature is the highlight, and works like a dream. Insert both SIM cards into the back of the phone – one slot works with 3G cards, the other with 2G only. Whenever you make a call, or send a text or email, you’ll be asked which SIM account you want to use. This allows you to select the network that offers a better call/message rate, while still receiving comms from the other SIM.

In some menus, such as SIM manager, you can also easily switch between the two SIM cards. On the home screen, tap either of the visible networks, and you’ll be taken to another screen where you can turn either of the cards off, as well as manage your Bluetooth and Wi-Fi connections. This is a useful function for those with separate business and social phone numbers, and Acer has implemented it perfectly.

 

User interface

 

The menu systems are overloaded with icons, particularly the widget menu. There are clear links to the organiser, internet, multimedia, tools and programs, but the above two rows of smaller widgets are harder to decipher.

It’s one of the least intuitive menu systems we’ve tried, and there’s literally no back button or function. In any of the menus, you won’t be able to go back one step – you can only press the call end button to return all the way to the ‘Today’ screen. Some shortcuts in the user menu help the phone’s usability though – tapping and holding the task bar launches the ‘Spb Shell’, while a quick swipe downwards returns you to the ‘Today’ screen or the last active app.

Messaging is slow to load, even without any text messages or media taking up the phone’s memory. The handwriting recognition and transcriber functions are interesting features – both are intuitive, and the transcriber can do cursive, printed and mixed sentences as well as letters, but the speed is far inferior to typing or even T9 texting. There is a full QWERTY soft keyboard, but the keys are too small for finger typing so you’re relegated to the stylus. Considering there are equally business-capable devices like the HTC Touch Pro2 and any BlackBerry that are usable stylus-free, this is a significant drawback.

 

The verdict

 

This is far more a PDA than it is a smartphone – the DX900 is full of desktop-like features but its user interface lets the phone down, particularly compared to the pedigree of multimedia-enabled, business-friendly handsets out today. Luckily, it gets top marks for its killer app and switches with ease between SIMs. As it’s one of the few dual-SIM phones around, we’d recommend this phone if two accounts in one phone is important; otherwise, an unintuitive UI completely lets the phone down.