I owned a pair of Pass XA-100.5 amps and went to a 30.8 because of the heat. I have a smallish room and the Pass amps are like space heaters. Something I don't need in Texas in the summer. I went through a plethora of amps including several McIntosh (heavy), Classe (not heavy), Cary, Krell (not as heavy or as hot as Pass and sound like Pass), Bryston and a few others.
In my opinion, the Bryston (4Bsst2) is the best bang for the buck. It sounds as good as the Pass, doesn't get hot and only weighs 50 pounds - almost 40 lbs less than the 30.8. Highly recommended. From what I have read, the 4Bsst3 sounds even more like the Pass.