For 2-ch system, I use NcoreMP, 6 channels (LXmini + subs) use 0.8 A (120VAC = 96W) including power to N130 - everything runs cold.
For HT system, the Denon X6400H (class A/B) runs so hot, I added a cooling fan, which is very noisy when it turns on, and is distracting while watching movies.
Having that experience, I avoid gear that needs cooling and/or is very inefficient for myself. I also wouldn't let heat prevent me from chosing gear that is worth the compromise - if I thought it was worth it.