I had such good sound with my Cab M at a concert the other day, that our singers turned around and told me that my sound was on fire! I think the preamp has a lot to do with it (I changed, now using Genzer Magellan and a Sushi Box More to get some tubes into the equation).
Also, I used to prepare my sound with headphones or a small PA speaker at home, and then the sound through the real PA was totally not what I expected. Then I got some good in-ear headphones and a good FRFR speaker, and the sound I prepare at home is identical to that we get FOH with the band. I've said this before, but my time during the sound check is ridiculously short because the sound is always right (unless I screw it up, but then I tell the team not to touch anything and I'll fix it on my side, which is usually pretty easy). But I agree, there are a lot of pieces to the puzzle and it might not be for everyone.