I had a nuon. I did the nuon-dome thing, downloading some decent homebrew games. Bought most of the commercial games, like Merlin Racing and such.
Not a great system, could have been. The developers sdk was and is poor, you can only use 2 of the four cores reliably, from what I understand.
Also, was a bummer that Bust a Move was created, but never sold. The nuon-dome site owner had a beta copy he showed off.
Merlin Racing was the only decent commercial game for it, as the tempest remake was hard for most people to get into, and there was also a slow doom port.