Funny isn't it how we all think differently...
I played at the weekend and the support band had a guitarist using a Marshall ( I think it was a JCM800 - certainly an older model, probably non master volume).
A few things struck me:
1) It sounded really good
2) He had it VERY loud - the PA guy had to get him to turn down a number of times as the backline was drowning out the PA. He was using both a 4 x12 and Fender Hotrod deluxe as a slave...
3) He had a pedal board the size of a small barge to give the additional sounds he needed, although he had some very creative sounds ( octavers, Moog thingies, strymon timeline delay etc).
So going on stage I thought my KPA doesn't sound as good through my 1 x12 FRFR...until i started playing...it sounded great, particularly out front, but not at ear splitting levels. Don't get me wrong, we don't play quietly, but I don't need to crank it. In fact I prefer not to be too loud else the Gretsch squeals like a pig at feeding time. I can balance the volume to get musical feedback.
I get the " its not got the amp in the room sound" but actually I prefer not having to deafen myself or the audience to get a great sound and I've changed my thinking as a result.