After two years of going crazy trying to get the kemper to sound good i have a few tips that worked for me
1. Use studio monitors or studio monitor headphones. Flat response.
2. I like to use direct profiles. Lasse and choptones are what i have found sound the best.
3. Use unboosted profiles then run a physical pedal infront of kemper. Be it a tube overdrive preamp or a 808 or clean boost.
I find it better to edit the signal here with more highs or mids ect then messing with profile eq.
4. Quality Ir
This makes or breaks the profile. I found 3 sigma audio make great packs. Bill kelliher asked them to profile his cabs for when he uses his helix as a fly rig. They sell his actual profiled cabs.
also lasse lamert cabs from his stl pack.
This really worked for me and hope maybe it might be helpful to some of you guys