They're not all made equal. I'm onto my 3rd now as the launch PS2 went wrong within 2 weeks, and it's replacement refused to read discs (laser voltage issue) around a year later. I've had a special edition silver model (big fat one) since, which has been flawless. My only annoyance is that it has capability to do 480P or better but no european games seem to support it. Especially GT4, which is pretty much the only game I still play. Shame as the US version can do it and 1080i etc IIRC.
I'd love to be able to load all my games onto the HDD (I have a suitable one and the network adapter), but I'm not sure how to do it. I have a feeling any methods may not be allowed to be discussed here, not sure.