I have the 4802 now and love it. That said, I haven't compared it to a Rotel IRD combination so I couldn't tell you how the two compare to one another. I tend to doubt the veracity with which some claim monos improve sound. I wouldn't be surprised to find that the isolation does remove noise, but I wonder whether that fact is dramatic enough to make a really profound difference, especially on speakers in this price bracket.
For me, it came down to the fact that the 4802 has three high bandwidth component inputs and all the processing formats I could hope for. If you decide to go that route, I'd recommend the 4802R which is the same product at the same price with the addition of THX Ultra2. If it's free, you might as well have it.
