agentcooper,
I moved from a Denon 2800 to the 990 (with a 755 providing the juice) and I noticed a pretty big improvement. Some items that changed..:
1. My 2800 had no digital inputs....990 does
2. I can hear a big improvement in the "seperation" of channels, I.e. each speaker is much more defined, and you can hear a bullet fly from left to right...
3. More options...many more than the 990, I really like the Upsample option, I am using it for my denon 380 cd player.
The only thing i had a little bit of trouble with was the size of the 990, it is much larger, and It required a little creative cutting (of the cabinet)
Over all I think that if you are going from a denon 2802 to the 990 you will see a big improvement. I can not speak to the rotel though...
Ian