Well, I have to admit, that I can understand the OPs intense. I really love my KPA and I definitely won´t change out that unit at all. But to my taste: when it comes to Marshall, I have not found one single rig that really does what my real (boosted) JMP 2204 does. To me, that specific Marshall-"emphasis" in the mids is missing. It works well for very "vintage" and very "modern" tones but not exactly how I hear Marshalls
My almost 100%-solution is one of the Britt Models through a different Cab from another rig. That does the job for me, but there are still 2% missing
When it comes to Britt profiles: I don´t like them when played alone or at lower volume. But like real amps: the work fine in the mix!