I'm a newbie with the Kemper, but I brought one home a week ago, programed my Ground Control MIDI controller so that I have access to 4 presets, and used the rest of the controllers as on/off for Tap, slots B,C,D, and all 4 of the Stereo effect blocks. I've loaded about 12 favorite rigs into the performance mode, and can access them 4 per midi bank, with on/off control of the effects (and tap tempo). The Ground Control also lets me run 2 pedals (Roland EV5's seem to work OK) for volume and wah/pitch.
Anyway, jumped into the fire last weekend and tried it live... without rehearsing with the band or running it through the PA. Here's what I found out the hard way. The output signal is WAY hot... I've since read further and see there's a way to cut down the output to the mixer, so that's my first change. I also discovered that the overdrive presets really don't seem to give you much of a 'boost' for leads... I should have made better use out of the volume pedal, but being a Mesa MK-V guy, I'm way to used to stepping on the lead boost switch. Anyway, I'll be experimenting with either some 'lead' volume presets, or get used to using the volume pedal. Anyway, back to the post... The GC allows you to stomp away in any way that suits you.