The Sony Ericsson P990 runs on Symbian OS 9.1 with the UIQ 3.0 software platform. dooyoo.co.uk reviews the Sony Ericsson P990i and writes, “The P990i sports a 2 megapixel camera with autofocus. The lens is protected behind a plastic disc that you rotate to activate the camera. While 2 megapixel is high for a phone, it is by no means comparable with the latest digital cameras and even some phones have surpassed this with 3 and 4 megapixels. But it is leaps and bounds better than the VGA-resolution cameras found on low-end camera phones, and can actually take pretty good pictures, just not in low light since there is no flash (there is a powerful LED that they like to call a flash, but all it is really good for is taking (very close) close-ups in low light). If you don’t plan on making any prints bigger than 10×15 cm, you are fine with this camera for everyday use. Of course the camera can also record video in standard 3G format. Due to the faster processor it actually does this in reasonable quality/framerate.”

GSMArena reviews the Sony Ericsson P990i and writes, “The right side of the phone houses the Opera web browser shortcut key, the camera shortcut key and the Memory Stick Duo slot cover. The Web browser key function can also be customized similarly to the Music player shortcut key - it can be set to open the Web browser, the Main menu, the Media player, the Sound recorder, the Task manager, or the Video phone application. When the flip is closed, pressing the camera shortcut keys turns on the LED on the back which otherwise serves as camera flash. It’s a convenient solution since you can use the LED as a flashlight. Since the Opera web browser works only in fullscreen mode you need to have the flip opened in order for the Web browser shortcut key to work. As opposed to all new Sony Ericsson models which leave the factory with the new M2 Memory Stick slot, this time the manufacturer has allowed the users to use the more popular Memory Stick Duo cards.”

InfoSync reviews the Sony Ericsson P990i and writes, “The screen of the P990 is excellent, sporting an improved resolution of 240 x 320 pixels and a 262K colour depth with impressive brightness and clarity. The user interface has been enhanced and now accomodates slightly more information as a result of the increased horizontal resolution, and the navigational paradigm has also been altered slightly - but not too much to make users feel as if though they’re on unfamiliar ground. ”

All about Symbin reviewsthe Sony Ericsson P990i and writes, “Connectivity-wise, the P990 will connect to your PC with USB, and any Memory Stick will show up as a mass storage device (but not the internal drive). Wi-Fi and 3G are available to get an Internet/data connection, and the GPRS/GSM frequencies are the standard triband of 900/1800 and 1900. A lot of people (including Steve and myself) are happy to see that the infrared port has been retained.”

CNET reviews the Sony Ericsson P990i and writes about keypad, “The keypad is one of the most notable design features of the P990i. The numerical keypad flips down to reveal a QWERTY keyboard on the main body of the phone. This is a big departure from the P910a, which had the keyboard on the flap itself. When flipped up, we found the buttons on the numerical keypad to be spacious and tactile for easy dialing. The keypad has the standard navigation keys placed along the top, which consist of two soft keys, a five-way navigation toggle, a back button, and a clear button. As for the QWERTY keyboard, we found the slightly rubberized keys easy enough to press, but they are so tiny and crowded together that it still took us a while before we felt comfortable typing with it. You also have the option of using the stylus for the handwriting-recognition feature for text entry if you prefer. Both the keypad and the keyboard have a blue backlight when activated.”