Hi
I've noticed that I tend to use much brighter profiles for live situations. And most of them were profiled with same guitar cab that I'm playing them through.
If you haven't done a profile yourself yet, I can only urge you to try. Your taste, your sound habits and your guitar might just be different from the "mainstream" and you might need to capture your sound first, to make the kemper as usable as your traditional rig.
For example: I wasn't too impressed with most of the quite dark sounding factory presets, so I tried if a profile of my Marshall DSL100 head would have the same "weaknesses" that I supposed the kemper would have.
I'm so glad I tried that when trying the kemper first, cause I wouldn't have bought it with the factory sounds I knew at that time.
The KPA changes heavily with the profiles you use, totally different than any other modelling device on the market.
L6,Vox,Zoom,11R all have their sonic fingerprint that you can't get rid of no matter what you adjust - BUT the Kemper simply does NOT have it's distinct fingerprint and that's the real beauty of the beast IMHO.
It sounds your way, you just need to make it to.
BTW The last time I switched on my tube heads was when profiling them...
René