I'm currently in love with the tc classic myself. The tube tone knob is really great in emulating a tube amp sag when you dig in. To my ear from 0 to noon it emulates a clean tube pre being mixed with the classic tc tone, which is nice for warm clean stuff, and after noon it gets gritty and more responsive to gain. If I dial the knob all the way to the right, and back down the gain since the gain setting for the SS pre causes quite a bit of overdrive, it sounds like an SVT, and behaves similarly when pushed.
The spectracomp being built in is a nice feature. It sounds good, not the best comp if you're a comp snob but good. Does its job as described with the multi band compression.
The only thing I'm wishing I had done different is use a little extra scratch and pick up the rh450 for the preset slots, but as a set and go amp, I live the classic.
I tried the GK, and I have an mb combo that I've played through my cabs. It does GK sound in spades if you dig GK sound, but if you want something fatter and warmer than you though solid state could give you then get the tc.