I bought a 450D from them a couple of years back. Looked like new but the focus screen was badly scratched and camera displayed an error (can't remember which) When I requested a replacement I was told that they wouldn't do that and I would have to return for a refund and "bid" on another one. The purchase was made by "buy it now" and they had more listed at the same price.
Basically I was a bit peeved at there refusal to sort it out in what I thought was the easiest/quickest way.
All that being said, there was no problem with the return and the refund but it wasted two weeks sorting it out. I would take the chance of ordering from them again but not if I 100% needed a working camera in a set time frame.