Don't listen to these guys. They just don't want to spend the money to do it right. Class D are for dining rooms, but only for dinner, unless of course you are playing disco. Class A/B are the best, they can be use almost anywhere, bedrooms, bathrooms. But only for Acid Rock, and Bach.
Please note, Acid Rock AND Bach, not one or the other. Class A/B switches back and forth. Without Bach there to pick up the slack on the rare times the Acid Rock level drops you could blow the whole amp. Still, it is so totally worth it, nothing does Acid Bach like Class A/B.