I personally never would buy a used device. Buy a new one with full and original warranty to be sure. My experience with Philips is good. My iPronto has been replaced for a new device, the first time I discovered a defect. Also I have good experiences with the iPronto-helpdesk.
My device works fine. I'm very satisfied with it. Some of us iPronto-users are now Beta-testers for Philips. Philips is very busy at the moment to "make things better". I can only say: BUY ONE. It's a magnificent machine!