GRRRRRRRRRRRRRRR..............All I can say is I hate the feeling when I can't hear the drummer and bassist because I have to crank my amp to sound good.
As for the scalable master volume designed amps oas is talking about, I just feel they're different monsters. Peter Diezel himself said,
YOU CANNOT REPLACE A CLASSIC DESIGN. So if you prefer your 180W Herbert for gigs, whether you're playing for Amoranto or some crampy bar like Magnet, then good for you. There is just something about cranked vintage-design tube amps that sound magical. I think a 15W tube amp for blues in a bar is loud enough. But for metal and rock, I think at least 30W. 50W for more deafening sounds.