I believe the quality of Adcom has declined over the years.
I, myself bought two Adcom GFA-555 Amplifiers back in the mid eighties, and have no problem with them, other than having to replace their power switches (both of them). They have state-of-the-art great sound. They served me for great quadriphonic sound untill I got the 950.I bought one more used about two years ago, and they are the heart of my system (along with the 950). I also had one of their two channel pre amps (GFP-565), which the 950 replaced. Can't speak for their processors. Heard they didn't sound too well. I know I considered their processord too, but soon forgot them, as they weren't up-to-date with features (such as multichannel inputs and EX/ES).
I understand they are finally coming out with a new up-to-date [finally] processor.