The top part of the phone hosts only the battery cover latch which works just fine.
The most distinctive part of this phone is the back. The camera lens and Xenon flash are revealed by sliding the dedicated cover. Sliding is very smooth and solid, and it immediately starts the camera. There is a slight resistance when starting to slide the active cover, but after the mid-point it goes all the way almost automatically. Thumbs up for both looks and handling here.
The loudspeaker grill lies almost unnoticeable just above the Sony Ericsson logo on the back.
Removing the battery cover (using the latch on top) unveils the standard Sony Ericsson BST-33 Li-Po battery with a capacity of 950 mAh. The same unit is widely used across a range of Sony Ericsson handsets.
The manufacturer claims the battery should provide up to 430 hours of standby and up to 9.5 hours of talk time in a GSM-only network.
In reality, battery life ranged over two to five days on a single charge, depending mainly on multimedia usage.
Also under the battery cover is the M2 memory card slot. It is hot-swappable, you just have to remove the back cover to access it. There is no eject mechanism so you’d better have some strong nails when trying to pull out the card.
The Sony Ericsson C901 is a sleek and compact bar. Those few handling issues we mentioned a few lines back aren’t a deal breaker and when it comes to shooting images (one of C901’s main tasks), the ergonomics come into their own .
The C901 interface is the regular Sony Ericsson feature phone UI that is used in most of their top handsets. To put it bluntly, the C901 offers nothing more than a few cosmetic tweaks over the elderly C902 - except for the addition of threaded messaging of course. It's also true though that it doesn't fall short of the Cyber-shot top dog, the C905.
The standby screen is arranged in the usual manner with information on top indicating signal strength, currently used data carrier and battery status. At the bottom of the display, just above the context keys are their labels.
The options for the menu layout are the standard foursome - theme-dependent, 3 x 4 grid of icons, rotating view and single icon view.
The rotating view features three animated front icons on the display, the center one showing the active selection. The other two icons are half-hidden, just as an indication of what comes next. Five other menu icons can be seen in the dim background.
The icon view displays a single icon at a time and a vertical bar featuring tiny icons for the other main menu entries. Neither of those view modes works with shortcut keys. Only the Grid view allows quick numeric keypad access.
The well-known Activity menu offers quick access to a user-defined list of favorite features, web, recent events and, of course, the Running Apps tab that takes care of multitasking.
You can minimize the progress indicator when receiving a file over Bluetooth but you can't do that when sending a file.
Flight mode can only work with a SIM card in the device and requires a restart.
The interface is visually appealing and snappy. Auto rotation is enabled in the Media Center and is generally quite responsive. There's a barely noticeable lag involved but we guess that's to be preferred over an over-sensitive accelerometer that can often play up.
Sony Ericsson C901 supports Flash Lite themes, which change the color scheme and wallpaper. Our handset has four themes preinstalled: Clarity, Cyber-shot, Peach, and Wink. The Cyber-shot theme was the most interesting one and is actually a slideshow of multiple preloaded images displayed on the homescreen.
Sony Ericsson handsets also come with a handy option for their wallpaper - you can use an application as a background instead of an actual image. Of course you can't just use any application - the choice is currently limited to a few apps. These are WalkMate, Standby World Clock 3D, Slideshow Wall and PIM Wallpaper. The step counting WalkMate and the PIM Wallpaper are probably the only practical apps among them.