Tubes, bias levels, preamp glass - they all play a huge role in how the amp feels and sounds. Any amp for that matter, but with me and my TJ and Rev.2, I went opposite all you gainernuts and reign back the gain using some 5751 tubes in the preamp section. What it did was remove the compression and opened it up to be an absolutely terrifying fucking device. Articulate, crushing, thick, and loud. Both my TJ and Rev.2 have benefitted from this tone-tuning.
My ears only, YMMV.
But whatever, great amps... Special. Not, like, "short bus" special but you know, "cool" special