I have not owned the 990 but the 970. I went from the 970 to the 2808 as the 970 was getting too glitchy. But aside from that the sound was very good for music and movies. In comparison to the Denon, I could n't say if it was better or worse but rather different. I currently use the 2808 and it works fine/sounds fine. It was an upgrade in terms of connectivity and codecs. All I hear is good things about the 990 from the SN platform. The 970 is a different platform altogether.

I am to understand that Denon should be coming out with a 3810 in a few months. It would be interesting to see how it compares to the 997/972. You asked for advice, I would wait until it is released before making any decisions to go with the 2809. The 3805 is a great (but dated) machine. If it still works you have the advantage of time to make a decision. In may case, the 970 was just too glitchy as it got older - the sounds emitting when switching sources via the speakers was really annoying so I was left with few choices at the time. Of course I will be interested in what SN/Outlaw have to offer in the near future.