Smittefar
Axe-Master
I have also never had any issues with levels changing, etc. I typically tweak a little at each gig depending on the room so I am used to adjusting gain, master volume and EQ settings using the knobs for certain presets on the fly as needed.
The level changes are not extremely big. It might be something like 3dB in either direction. If you are running only a few preset and tweaking them at soundcheck, it would never be a problem. We usually run without soundcheck and without sound guy. I have one preset per song, and the levels are all saved with the preset. So level changes required me to update 60+ presets. I have a system, so it is fairly easy to do but tedious none the less.