Alright so as far as the two cars, they pretty different animals I think. The 335i had the luxury, seats were more comfortable, power, adjustable side and leg bolsters, back supports, all that. Interior nicer, I wish the STI had leather seats but they are nice, just the 335 was all leather. I do like the color scheme in the STI better, the 335 was not bad though, mine had the black interior with silver dash and door trim. Material inside, nicer on the 335. Ride comfort - maybe a little better in the 335 but I had the sport suspension package so the ride is going to be a little firmer than a nonsport suspension 335. But then again my first cars were Mustangs so a rough ride doesn't bother me. Even a coworker who has been in my old Mustang (a '03 Mach 1), the 335, and the STI, said the STI felt like my Mustang. I don't mind though. Lets you feel the road. Brakes - so far the 335 had better brakes but I think I need new pads and if I switch to a better pad I will get that initial bite that I like. Not that the STis are a slouch, just coming from the 335 I felt there was something wrong, even took it in to the dealer to see if there was a problem. I have gotten used to them now though. Power - what matters most hahaha...well coming from the 335 with the mods it had, definitely the 335 over the STI (as of now) but that's not fair. The tuner on the 335 would allow to run a mix of 93 with a few gallons of E85 so got a few more ponies out of it, definitely noticeable. Mine was an auto but always felt like it was in the right gear. When I bought it it already had the dual cone and the JB4 (I saw the intake but wasn't aware of the tuner). When I added the downpipes that definitely woke the car up. Parts can be expensive though, as well as repairs if out of warranty. If your battery dies, expect about $600 through the dealer. That includes the battery plus the registering of the battery with the car so that the car won't overcharge the car. Crap but necessary. If you want to swap out the stereo, good luck. The stock head unit is needed to do some updates/programming with the car so you either have to move it elsewhere in the car or reinstall it if you take the car if for servicing. Mine was a 2007 and I would get a squealing noise from what people think is the rear brakes but when you are accelerating is when it would happen. Something about the design of the brakes some people get unlucky and get it some don't. I was a little let down when I first got the STI because I was afraid to drive it in Sport# mode but since then I am happy. I now drive it in Sport# daily. Its my daily driver and couldn't be happier..other than the rattles but looking to try get rid of those this long weekend. Plus the exhaust sounds nice even stock than the 335. And you don't feel like a douche driving around in a BMW lol. Plus the Subaru/WRX/STI community seems to be more what I was used to in the Mustang community. Get waves from other Subaru owners all the time. Never got that in the 335. I have no regrets trading over to the STI. They are pretty different cars though. Just depends on what they want. Let me know if they have any questions about owning them though.