After reading a couple of mag review on STi & Evo, I think Evo would have similar characteristics as an R on the streets & at the track.

But, strictly comparing an STi & an R, I would keep the R if it's my weekend/autoX/track car. If it's for everyday driving, I would much rather have a 4-dr w/ 300hp. ITR isn't that comfortable to commute in. I've done it for 9 months straight and it wasn't comfortable. (hash suspension on local roads + lack of torque)

If I had $35k and had an option of choosing between the two (both new), I would probably try out the STi (for daily driver + weekend/autoX/track). If you don't like it, sell it and get an R.