Never buy based on design, etc. Buy based on how it sounds. All this other stuff, heat output, etc, may or may not matter depending on your situation. ie small room, poor ventilation, hot weather, probably not the best place to put a 500 watt heater. Unless maybe it puts out music that is to die for. Which you will only know one way, by listening.
What are the advantages to a Class A amp & what are the trade offs?
I've never had a class a amp but am considering one now. So what am I getting myself into?