Headroom with a little dirt plus available crunch; nothing too high-gain. Reviews say this has a nice clean channel, and the Creamback seems to be universally well-liked.
My issues with tube amps are very personal - most of them drive me crazy between hum, rattles (both easil-solved and mystery), plus the widely-varying quality of the tubes themselves. I have tried out and am thinking of going with the Orange CR60C, which is the SS version of the Rockerverb. It had good cleans, and the OD channel is surprisingly tubeish and not fizzy.
I know that nothing sounds as good as a good tube amp, but SS would eliminate most of the personal irritants.