Well its been over a month I have been using Sony Ericsson K508i... Few experiences and suggestions:
If you have signal problem, SE is a definite no-no. Nothing beats the Nokia in the signal reception
One more problem that I have come across is the phonebook. Even if I'v stored a number in the phonebook, it does not appear when the person calls. This happens with random nos. The service centre people told me that I need to update the s/w.
There is no way you can delete the inbuilt games. This is frustrating as the cell comes with Demo ver.of Splinter cell and you can easily finish the demo in 2 min. Tennis, Darts, Fighter though are full ver., they cannot be deleted.
you will need to charge your cell almost everyday! When I asked the service centre ppl, they told me that I should charge the phone even after the battery icon shows full (which happens in around 2 hrs.). In that case you need to charge the cell for around 3-4hrs.
If you want to test your cell, remove the sim, switch it on and press * and then <- (joystick). This will take you to service test, options, etc. Very good feature. you can chk your camera, vibration, vol.,display, etc.It gives you all the details about the cell as well.