There’s a a big difference in playing at moderate volumes in Madison Square Basement by yourself vs opening an amp up at a venue with a full band or cranking in the studio, and I don’t think we differentiate enough when making these comparisons.
There’s a lot of “in the room” difference among amps when all you hear is you in your room. I think the “not much difference” applies to the other scenarios, and the moment you start using IRs, putting boosts in front, etc…it gets minimized even more.
I don’t think Meshuggah had any trouble getting Rev Gs to sound tight with a TC in front, nor do I think the revision they used on “Chaosphere” (for example) would have mattered at all in terms of tightness and tone, given the player, the studio setting, the boost, etc. That album would sound 99% the same regardless.