I'm late to the party again, had my Kemper for right at two years now. Still the best gear related purchase I have made in a long time. Couple random things that may or may have not been discussed:
When you profile an amp, you can compare the kemper's profile with the actual amp right then and there. If it doesn't match, you'll know it immediately. This is a huge plus to me - the amps in the Kemper sound like what you're feeding them. It can make for some bad profiles sure, but you can also find some excellent ones too. Had a friend come over last week, huge tube amp guy - brought a sweet GT Soul-O amp. We miked it up in my main room, ran it through the monitors, he agreed it sounded good. Ran a kemper profile, compared them on the spot - and let him play while I switched back and forth. He's owned this amp since 2006, got it right once out of three tries regarding which was his amp - including rolling the volume back, changing pickups, etc. Told me afterwards he was totally guessing.
I was an early adopter of the 'direct output' profile stuff. My personal findings is that a tube amp still sounds better than solid state for the kemper when you amplify it through a guitar cab. On that basis alone I'd personally pass on a built in power amp solution unless you weren't going to use it often. I took my '72 Marshall, took a line out from a hot plate and profiled with it. Then I took an A/B box and one side was Kemper - poweramp (rocktron velocity solid state) - 72 marshall slant cab. Other side was 72 Marshall - 72 marshall straight cab. The Kemper sounded fine until I clicked to the marshall. It sounded better. I replaced the velocity solid state amp with a Randall 2/50 tube amp, tried it again, was able to adjust the presence and depth a hair and they matched much better - I wouldn't have been able to tell at that point. Maybe the Kemper power amp is full of magical goodness, but it's more than just making something loud IMHO. I've done the solid state amp with tube preamp thing before, it doesn't seem to do as well either, ya know?
I also don't get how the Axe II guys talk about how they make their presets from scratch. They still need to choose an amp emulation and then tweak it - which is the same thing the Kemper guys do. Difference is, I may go onto the Kemper website and see a new amp posted there that has only been out a few days. For the Axe guys to get it, they need to send one to Cliff or hope he has access to one, he has to create the behind the scenes stuff that makes an amp in the axe fx world, and then release it via a firmware update.
And if you are a tweaker, you can take an amp and twist the hell out of it. The EQ not being the same as the host amp never bothered me, because the Kemper has several different EQs and you can place them post or pre amplifier PLUS the amplifier tone controls, which as of the latest firmware is also able to be placed early or late in the amp's topology.
Here are a few of my weird clips of the kemper - when it's a backing track with guitar, the backing had zero guitar. You're hearing all kemper, all the time for better or for worse. Put some stuff in here that's not quite as metal/hard rock as most of the Kemper clips are just for some contrast.
https://soundcloud.com/okstrat/point-of-know-return (I did all the tracks on this, midi drums with SSD, bass and all guitars were kemper)
https://soundcloud.com/okstrat/02-sympt ... e-universe (live, first gig I played with the Kemper, had it less than a week)
https://soundcloud.com/okstrat/room-335-fuchs
https://soundcloud.com/okstrat/purple-haze-kemper