Like the 2400c, the owners here in Japan are rather fanatical about the 550c so they're rarely found in poor shape; they're usually pampered and handled gingerly. I have a few of them and none have plastics-related problems, though one is currently inop owing to a bubbled display. One has obviously spent its entire existence in a Wetsuit case, judging by the light wear marks in the computer corresponding to the internal straps on the case. As mentioned, they do still occasionally suffer from display bubbling, and leaked batteries are always a hazard if not caught in time.