I've had an STI for the last 2 years, and there's always the battle between the Evo and the STI, so basically we have covered all topics between those cars... its kinda like this
Evo pros:
-Very fast steering
-Excellent track-day car
-Excellent stock tires (Yokohama Advan A046s for the win)
-Excellent brakes (Brembo 4-pots front, 2 pot rear)
-Tight and precise tranmission feel (the 6-speed in the EvoMR especially)
-Tight suspension
-Extremely moddable engine (the inline-4 turbo 4G63 has been around for quite some time), you make good power with little money
-Excellent seats (those Recaros kick ass)
-Front mount intercooler less prone to heat soaking (compared to the STIs top mount IC)
Evo cons:
-Very harsh suspension for a daily driver
-Reliability issues galore (mostly premature clutch failures and excessive wear is what I've seen commonly)
-Noticeable turbo lag
-Low rent interior
I could talk all day about the STI, but you're looking for Evo info mostly. I do not have one, nor driven one, however we discuss about the Evo every single day in the STI boards and this is what comes out as conclusions most of the time