To my mind, the KPA comes off like two separate products from two separate divisions - the Profiling part vs. the OS/implementation part. The Profiling part scores very high indeed, while the foundational OS/structure tends to be barely treading water. Somewhat like the star quarterback who keeps throwing perfect passes, but the receiver can't seem to hold onto the ball...
I don't know the history of the Kemper software development, but I would guess it was pretty focused on the Profiling aspect - this produced a fantastic result, but it still needs enforcement and support from the rest of the package.
Comparison comment between AFX II and the KPA:
They both can sound *Great*, no doubt about it!
The Kemper gets *very* amplike sounds right off the bat, and has a huge number of quality profiles to download - there are still too many noise problems for what I do, but the basic sound is certainly there in spades! I was somewhat disappointed to find that it did not respond to Pre-EQ very effectively (or at least not like most of my tube amps) - it was almost like the KPA was on a mission, and that mission was to sound like *that amp*, come hell or high water.
The AFX II is a very different monster. I treat it like I do most of my tube amps - I use both Pre and Post EQ to effect the desired result. I find the AFX responds almost exactly like my tube amps to this technique, and all this can be done within the unit with no outboard assistance. This results in a huge number of different but highly usable sounds that I can tweak as needed.
I am a fortunate man to own both, and I look forward to the future advances from each platform - these are truly GREAT days to be a guitarist!