The current behavior of your Ayre is of interest. But, more power produces an effortless transient attack that really makes music work emotionally.To the best of my knowledge, Ayre, Theta and, maybe Dartzeel are the only manufacturers of SS zero-feedback amps. The Ayre VX-5 stereo amp has a bit more power than my AX-5 integrated (rated at 300 W into 4 Ohm). Stereophile measured the MX-R (non Twenty version) at 595 W into 4 Ohms and 720 W into 2 Ohms - but that product is WAY beyond my budget. The Theta Citadel ($12K) is rated at 400 W into 8 Ohm and 800 into 2 Ohms. The Dartzeels are generally more expensive than Ayre or Theta and also less powerful other than the $150K behemoth reviewed by Fremer (1025 W into 2 Ohms!). I wonder how *that* would sound driving a modded pair of CS3.7s!
I think there are a handful of tubed zero feedback designs but these are probably less powerful than the above. And with that I apologize for taking the "Thiel owners thread" off topic!