Of course our STAGE volume isn't that high. I never said it was. That's one of the main reasons we're 100% digital: better control of stage volume. FOH volume is why I say to tell the FOH guy if you're using presets. Luckily, we have our own engineer that moves the sliders at shows even when it's not our desk. But, even after using the Axe on stage for years, he will still tell me things like, "You're heavy trem patch was a little hot. I had to pull that down pretty quick." At which point, I make a note to adjust it back at the rehearsal room. This is especially true after a firmware update when all the levels may have changed. I'm not sure where you're playing but we played several festivals this summer where every band was going out at 103 - 105 db at the mix position at FOH. Yes, it can cause hearing damage. Ever heard of Pink Floyd or The Who? They tune up at 105db. I'm not sure of your experience level but it's hard NOT to be at 103 db stage volume when you're sharing the stage with a rock drummer.
Taking notes is a good advice, no matter what. Still, I'd say you can get pretty much in the ballpark when rehearsing at reasonable levels. I never experienced any sudden drop or jump in volume live after setting all my preset levels at rehearsal.
And of course, you have to take care of your levels after major firmware updates. Even when it's not written in the release notes, I always make sure I got at least one rehearsal between a firmware switch and a live day just to go sure everything works fine. Doing otherwise would be careless.
I don't care that there are big bands destroying their audience's hearing for decades like The Who or PF. I - as a musician and caring person - feel responsible for the health of my audience. They do not have control over the volume or dangerous high frequencies. But I have.
I don't want anyone to suffer from severe tinnitus after a concert and I feel that every other musician should do the same. It's just a medieval practice to turn it up to eleven.
Heck, it's 2014. And with the high quality Line-Arrays we got nowadays, you can get crystal-clear sound traveling over ridicolous distances at reasonable levels.
At the last festival I was, the international headliner went to insane 112 dB (measure with my phone, so well, take it with a grain of salt) - at a distance of more than 50 meters from stage.
The underdog local band playing two hours earlier scored a reasonable 97 dB. Do I need to say that the sound of the latter was much better? Maybe the reason for that was that people in the crowd did not need to wear earplugs and could actually hear the vocals...
If you need to tune up to 105dB just to hear your own playing over the drumming, then your drummer is doing something terribly wrong (especially since you "played several festivals", where I assume the stage is not the size of a parking cell, so you can keep a reasonable distance. And when playing smaller venues, it's a good advice for any drummer to discard the sledgehammer playing and go easy on those cymbals.
I played around with the I/O input level just to satisfy my curiousity and did not notice any difference in sound (I noticed a slight difference at 100%, though).
The input trim of a mixing console and the Axe are apples and oranges and you know that. No need to get snotty.
Even Cliff keeps telling the users to set it to the level of the hottest guitar and then never touch it again.