Congrats. Iv had my 09 WRX hatch for almost 3 weeks now and i absolutely love it.
i orderd the perrin catback this week and honestly it sounds way better than the SPT exhaust. To me the spt sounds way to muffled. The vids on perrins web site for the 08 WRX sounds awesome, the perfect boxer rumble if you ask me. My catback is scheduled for deliver on monday. Cant wait to install. I cant stand the sound of a stock WRX. Its just not right to have a boxer engine without the rumble.
Dont worry to much about a cat back voiding your warranty. Your car came with a catback exhaust from the factory didnt it? YEP. Catback are for sound and wont hurt your car.