I run the 4's and I enjoy them very much. I autocross on them and I run -2.5/f -1.5/r camber. I have not noticed excessive wear. The tires are predictable in corners, they take a nice set and stay there, whereas the stocks would hop or slide without as much warning because the sidewall was so much stiffer. The 4's are quieter, and cheaper as well. I have found them for $88 each for the 215/45/17. Treadwear is 300, not as soft as the Azenis or the Kumho MX, but pretty sticky. I have 6000+ miles on them so far. I placed first in every autocross event I entered last year in STX against Azenis shod WRXs.
I had the KDs on my SRT-4 and didn't care for them much. I was going to switch to the 4's on it as well.
My brother has the 4's on his Mazda 3 and he is cleaning up in local CSP against R-compound Miatas. Don't ask me how though!
Britt