Yeah I actually gig with my Trademark 10. I run a Rapco A/B box with the 5150 on A and the Trademark 10 on B. I use the Trademark 10 for all my clean sounds. I run XLR output to the board, and the sound guy gives it back to me in my monitor.
I tried the Trademark 300 because I thought if the 10 sounded that good, the 300 would sound great. Boy was I wrong. I have figured out quite by accident that if you run your effects send from your Trademark 10 into a tube power amp, and then into a closed cabinet, it is the most awesome sounding amp ever.
At a gig one night, one of the pre-amp tubes on my 5150 took a crap, so with my limited knowledge of electronics, I theorized that if I ran a patch cable from the effects send of the Trademark 10 to the effects return of my 5150 combo, I should be able to use the power section of the 5150 combo with the pre-amp section of the Trademark 10. The results were amazing. First of all, none of the controls on the 5150 were active anymore, all of the volume control was done at the Trademark 10. Secondly, I found that I liked the tone better if I turned the cabinet emulator switch to flat, and let the natural resonance of the 5150 cabinet take over.
The rig in that configuration, I thought, sounded better than the 5150 did stock. The only problem was, I was a little concerned that running my amp that way for long periods of time may damage my 5150, so I had it re-tubed and now I A/B the two amps.