Oh this discussion is interesting.
I have never used a cab with the Kemper but today I was setting different outputs for Reamping, using my DXR10 and a 2x12 with GT-75s in so I can account for various situations.
I have never used a cab so I gave it a go at low volume. Loads up Deadlights JVM profile as I own that physical amp, disabled the cab and it sounded fantastic. Tested the AFD and Mesa and the AFD sounded OK (needs v30s) and the Mesa sounded terrible (again wrong physical cab)
It is amazing how much the cab effects the sound and until I owned the Kemper I had no idea.
The Kemper still amazes me.
Mike