At one point, I was using all ARC tube amps for my home theatre. (I didn't leave them on all the time, of course). The system consisted of a very old Dual 75a that I have owned since the early 70's, a Classic 60 that was relatively new, and a large monoblock that I purpose bought to use as a center channel amp. (the woofers, a pair of velodynes, were self-powered).
The system sounded great with Snell speakers, but it was HOT after a few hours in the viewing room. I have slowly migrated away, first switching to solid state for the rears, then eventually all channels. I now use a large McIntosh multi-channel amp with oodles of power, and, at least for home theatre use, it sounds great. (My music system is not part of this theater system). I still use tubes in the audio system, but that's another story.