The hard rubberized plastic case is trash! I've owned one for a couple of weeks now, and the tiny plastic tabs that hold the case on the phone are starting to systematically break off... from normal openning/closing of the keyboard.

I've had the PDair hard rubber case for about a month now & no problems at all with regular use, including above normal keyboard use (i'm a mad txtr/e-mailer/internet fiend)
Also, I've snapped it off & on multiple times to fully clean the screen &/or get to the SIM & memory card.. never a problem there either..