That's all well and good, but in my experience
A) Every next room is entirely different (as pointed out)
and without
B) A FIRST-rate FOH guy that really knows his system, you're screwed.
I completely understand how Jimmy J uses the setup he does. Bring your favorite amp, get your onstage sound perfect to your ears, and then the band complains, you screw up the mains, the room rumbles as you bleed over everyting, just not often when the stars align and everyone is happy. I'm tickled I spent all this money on a big rig I can't use. Bring the combo, and all I hear is snare and his Marshall half-stack.
The 600# gorilla in all of this is all these basses with 3-band EQ piling into bass amps with more EQ than most channel strips. Back off the deep end and boost your mids . . . . really. And thumb it till the VU needles bend. OK . . . .
I could never hear myself properly, I was never satsified with my tone, and it drove me out of ever gigging again. Physics have conspired against me. Standing waves, anyone?
J o e y