I and a few others bought their Denon 3805 from this same site a few years ago, and to this day, I don't think any of us had issues with our receivers. The remote control on these units had a few quirks, and Ubid along with Denon have exchanged the remotes, as well as extended the warranty on the remotes for two years - including refurbished units with 90 day warranties.
These units are as good, or better than new since they've had the twice over.