I used it with my old Kenwood KM-X1 THX Ultra 100W x 6 channel amp.

At the time I was looking for a replacement of my Kenwood KM-C1 prepro that died. I eventually went with Integra Research RDC-7.1 as I was able to get Onkyo employee discount on it.

I liked the 990, but felt it was a bit unpolished because of little things like the popping noises. That and lack of coax digital inputs led me to get the RDC-7.1.

Although I'd have to say that you get more for your money on the 990 at (then) $1100 vs the RDC-7.1 at $2500 (which is what I paid for it). I wouldn't pay full price for the RDC...in fact, now that they've said they aren't coming out with any upgraded modules, I'd be downright pissed if I spent $5000 on it.