I use the Kemper to reproduce live the sound of my studio records.
I set the the Kemper to sound thru the venue's sound system (mixer) and the output without power/cab sim thru an art-sla2 solid state power amp and a Bogner 4x12 cabinet to feel the music on stage. (+ in ear tweaked general mix)
For small gigs, direct to the mixing table + in-ear mix.
I'm very pleased with the results
PD: I used to go with a 3 amp setup + FX rack (bogner xct classic + VHT/FRYETTE sig X + soldano slo30 or a marshall silver jubilee) + bogner 4x12 (celestion v30) cab + brunetti XL 2x12 (jensen) cab for "big gigs" and a jet cicy 20 or a marshall silver jubilee 2525h + brunetti 2x12 cab for the small ones