I like the interior of the STI over the Current EVO. They are both 5 years behind anything else in the segment as far as ergos go. As I get older that matters a little more.
PSUpunk, I would agree the ST has more rear luggage space than the GTI, but the GTI has more rear seat leg room. The folks at VW just scooted the seats back, which I think is actually smarter. Having more rear seat leg room is more important than trunk area, since you can always drop the rear seats when you need to haul something larger.
This car is truly more than a match for the GTI or MS3. I think the real choice is WRX or Focus ST. You can throw in the STI and Golf R in the mix as well.