I really enjoyed this thread. The 'use your ears' line that is typically thrown around in the forum is of course vital, but in terms of finding a way forward in a tone search, my ears are only going to tell me either "sounds good", or "keep searching". It doesn't provide much of a game plan.
Using your ears is definitely the way it will ultimately go but I bet all of us have felt pretty lost after going through at least hundreds of IRs. Ear fatigue is pretty drastic when going through IRs which are basically different EQ filters. What I found was that I usually ended up with something that's a bit too scooped for a mix and not enough clarity so it's kind of like the difference when you tweak a guitar amp on your own but then when you're playing in a mix you have to change your tone completely.
Once you have these mixed IRs that are all "scientifically perfect" you have so much interesting variety and you'll most likely sound amazing. F.ex. everyone (including me) swears by the Celestion Vintage 30 but yesterday we were at rehearsals with my band's other guitarist who also has an Axe-Fx II. We were both using V30 IRs and things sounded amazing but I came up with this "FUV30MIX" ( ) which was basically a 1960A mix blended with a G12H30 mix and it gave us so much more separation although we both sounded equally balanced and good.
And that made me fall in love with speakers which I usually struggle with.
Those are Redwirez mixes by the way:
Redwirez Marshall 1960A:
PR30 CapEdge 6in
U87 CapEdge 4in
R121 CapEdge 5in
421 Cap 6in
SM57 Cone 0in
Redwirez G12H30:
M160 Cap 4in
PR30 Cone 1in
U87 CapEdge 6in
R121 CapEdge 0in
421 Cone 1in
SM57 Cone 3in
And I think I have a reputation of not really liking Redwirez on this forum. Single mic positions never really struck me as awesome. These mixes however work great!