I was a long time DSM/EVO community member prior to getting my ///M. I owned a couple of DSMs and an EVO. The 4G63 is a gem of a turbo motor because it's so mod friendly and reliable. The stock motors could push 400+whp pretty easily.
The evos definitely give a lot of bang for the buck in terms of performance. They're awesome at the track. They're easy to drive at the limit and the AWD system covers up many driver mistakes. Relatively new drivers can turn some serious lap times in these things.
I knew my days were numbered in the EVO when I started getting irritated by how uncomfortable the car was on the street. The loud exhaust, road noise, and bouncy ride never bothered me before, as they were sacrifices I was willing to make to be fast at the track. I guess it was just age catching up to me. I searched long and hard to find a worthy replacement for my EVO. I didn't want to take a step back in performance, so the ///M was a natural choice. Plus I've always wanted an M3 ever since high school.