Well I dunno. I feel like I get the best of both with tube & SS amps. As mentioned, I run the tube amps in cooler weather, so the heat isn't a problem then. Their like space heaters in a way. A friend of mine jokes that I could use them with a rotisserie above them. And then in summer months its the SS amp. The Hafler I have does tend to run warm if I use it a while. But not like the tube amps. I like the change up with certain aspects of the sound scape from either of the two types of amplifiers too.