First unit lasted almost two years then started having trouble with playback from EHD. Replaced and have had no trouble since.
I'm on my 6th now since March 2006, believe it or not. In order:
1) spontaneous reboots, became worse over time
2) spontaneous reboots straight out of the box
3) HDMI kicked the bucket and after several months, got a new one
4) spontaneous reboots, became worse over time to the point where that is all it ever did
5) spontaneous reboots, straight out of the box
6) so far, so good, though the 2nd night I had it, it gave me the catastrophic disk failure message--one hard reboot and haven't had a problem since
It is in a very well-ventilated area, so that shouldn't be the problem, but when #5 showed up in the condition it did, I almost called and canceled in order to activate D*.