The fact that you're unable to use or edit the Kemper and get a good tone out of it only proves your inabilities, with all due respect.
I'm not going to be harsh, but by God, how can anyone not be able to get a good tone from the Kemper is beyond comprehension. Kemper should be renamed "Good Tones for Dummies" and it's honestly quite embarrassing not being able to get a satisfying tone from it. Thousands of players are getting stunning tones for the whole world to listen to and enjoy but all you can muster is congestion.
I don't get why some people always try the worse case scenario and then claim that things don't work. If you haven't been able to learn the Kemper, then it's your fail! Move on or post some good tones that you produced with real tube amps, and
I'll put my money on it that those tube tones that you produce with real tube amps will suffer from the same congestion and mosquito attacks you claim are because of the KPA.
There have been many tests by now with different amps (with different people refining, for that matter) that show these differences though between kemper and amp. If I can reproduce these things pretty much every time I profile an amp (unless super clean tone) then I don't know what to think, really -- maybe I'm doing something wrong -- but it's not like support has given different advice to "refine better, with strong chords" on that end (which is good advice too if it comes to refining). Also @SonicExporer hears the effects in the clip I just posted. So there's a tube amp that does not suffer from the same issues we see with the profiles.
All that said I don't think there's a substitution to profiling one's own amps and seeing what happens then. Perceptions of what a "good tone" is vary a lot, obviously, and I do think there are many who prefer kemper tones to the real amps to begin with. It's a different experience to play through already made profiles and then have one's amp next to kpa and be able to compare without any cab sound coming in the way -- which is why I strongly encourage people to do some research and profile themselves before any conclusions about KPA either away around. I think that's the real test, which is no wonder considering the company even having an A/B function, encouraging comparisons.