Tried out the rack system on Saturday night, results were interesting. The venue is one we've played numerous times, so it was a good place for the debut. It is definitely clearer and more responsive on stage; I heard it fine and although it was very loud it was stable all night, I never had to turn it up or adjust anything; I suspect that was due to the headroom involved, because when you start turning up the Twin or the guitar volume the character of the sound seems to change as you are using the power tunes harder; the rack was just the same no matter what.
The soundguy remarked that it didn't have the "warmth" of the Twin head; I was a little worried about that, but listening to the boards it sounds nice.
It was the Resurrection Tiger into a stock Trio, Peavey Valverb tube reverb unit and a Crown XLS-402 450 watt power amp, 2 12" E120s in a Hard Truckers cabinet. Effects were the usual -- QTron, OD2-r, Octave, Phase 100, DD6 delay and Boss EQ.
Interestingly, at low volumes in my house it sounded crystal clear without a trace of dirt or overdrive; on the tapes, it has a certain amount of drive to it. Not sure if that was the louder volumes -- at home, I could only put the power amp on 2 without blowing my ears, at the venue, it was on about 4, running the JBLs harder (one of mine is suspect at the moment), or the board/microphone combo being overdriven. Hmmm.