My friend had two WRX STis, a 2004 sedan and a 2008 5door. He had issues with both (burning oil, suspension clunking).
The interior (of the 2008) felt a lot like my Mazdaspeed3 or a Toyota Corolla. I couldn't believe it cost over $12,000 more than my Mazda.
I would say, if you don't need the AWD, save $12k and get the Mazdaspeed3 instead. Performance is comparable as well as size and standard features.
But if you must stay with a Subaru, just go with the standard WRX. It's a lot cheaper and performance wise its on par, if not BETTER than the STi. Check out Car & Driver's test:
http://www.caranddriver.com/reviews/2009-subaru-impreza-wrx-short-take-road-test