Hi there! I am a newbie but I tried to find a good solution for me and I have to agree with joshriggs. I did not buy the KPA for linear reasons only. I bought it, because I wanted to have a good sounding and versatile solution. I had a Headrush and it sounded great even if it was a 8" version. What I realized was, that this is not a guitar sounding solution, it is more of a studio sounding solution. Since I did not wanted to loose much of the linear part of it, I choose to try The Laney LFR 112 as it is something in between a real cab and a studio monitor. It is a real difference and I did not expect that. Is it good? I cannot say as good is subjective. To me it is more a guitar sound I was used to have but with all the advantage of the KPA. With the Headrush I had a cleaner studio sound, this is certainly nice to have but to me, not nice to jam with. Studio Monitors are made for Studio use and all the stuff you want to achieve in a Studio. The Laney to me is the best solution for just playing at home or with the band.
I had a Studiotone 20 for many years and I did know every characteristic of its sound. I bought the Profile from a Studio, removed the Orange cab in the profile and there it is, my lovely Studiotone20 I had but even better. More balanced if I could describe it in a simple way.
Hope this helps others to make their decisions as it is IMHO more about what you want to do with the KPA then what speakers are best but simply not ignoring the linear part of the game at all.