Never really had a volume issue with my SVT-3Pro.
Took a little time to find EQ setting(s) that I really liked and decided to stick with, and that also helped. But, I'd never say this amp was lacking power for it's rating.
I usually run mine with a SVT 410HE (sometimes with a SVT 15E), and I think it's great. For the gigs I play, I can't imagine needing more stage volume or headroom (biggest venues are maybe 150-175 seaters) and almost always plugged into the house system anyway - either the XLR-in on the amp, or DI with my SansAmp BDDI.