In reply to:
The humming and the heat sound like deal killers to me.
This is why i'm waffling on the decision.
The heat may not be a big deal since you normally do not sit touching the amp while listening to music. Perhaps in a small room it would add some temperature but otherwise, who would really care if it ran a bit warmer than some other amps?
It is Class A into the first 5W which i'm sure is part of the issue.
The hum, as far as i can tell, does not affect the sound quality any. The noise floor from recordings is greater than the hum but the mere fact i know it is there is bothersome.
But i love everything else about the Halo.
More waffling...