I stepped into the world of BMW after a stint in the Audi scene (2005 S4 to be exact), an extremely costly maintenance stint. Being a little short-sighted, fueled by Audi frustrations, I honed in on the M3 without doing much cross shopping. I didn't bother looking at anything resembling an automatic which threw out Mercedes (c63 AMG) and Lexus (IS-F), both extremely sexy cars, which were really the only competitors in that price range. The BMW 335is had just come out, which I was allowed to test drive but the fact that regular 3-series cars are everywhere in the north east, swayed my decision to go with a loaded M3. Well, that and the price difference between the 335is and a loaded M3 was on the order of $10,000 - something I was very willing to spend knowing the ///M racing heritage and aggressive, yet sleek styling on the M3. That's not the whole truth, a guy I worked with just picked up a 335i and I wasn't about to get the same car as him!
The M3 was my first new car buying experience and boy was it informative. Hours spent searching online, gathering details on how I could squeeze every cent out of that dealer and get the best price. When I showed up at the dealer, I came prepared with invoice pricing sheets, offers from internet dealers, even my fancy pad folio and $50 pen to seal the deal. I was a little turned off by this specific dealer because it was obvious that I knew more of the technical details concerning the car than he did, often misquoting product details or flaunting their dealership's "Gold Sales Status" or some other fake sounding award. It's a little weird, only because every BMW dealership I have ever been to brags about how they are the best one around in sales and service - give me a break, not everyone can be the best. One demerit
With BMW came an extremely personalized run through of all the cool gadgets, gizmos, pressure switches, and buttons found through out the cabin. Details that would all require a run through of the user manual to get back to the same screens.
The s65 motor in the M3 is an awesome, high revving V8 that sounded like pure sex at the 8,300 redline but lacked any real killing power on the streets, especially in a younger area riddled with STI's, Evo's, and bad ass modded 335i's making more power than you. Hell, I got beat up on by a turbo Integra one night. The 0-60 of 3.9 is what is published everywhere but can't confirm as I had the 6 speed and those numbers where for the DCT version. In terms of modifications, there isn't much room to play in the engine bay limiting your options. Sure you could do a full exhaust, tune, and a few other little things but you'd be hard pressed to make more than 400rwhp (stock cars will dyno at around 300-340rwhp). Yea, there is always the blower option which would put you into the 550ish range and lots of people have had great success going that route. It's a fight to get any sort of real power out of the car without heading down the supercharger road. It was the fastest car I had ever been in - that is until I took the GT-R for a spin
What the GT-R lacks in luxury items it makes up for in raw performance, even in porker status (3,800 curb weight - so figure 4,200 after fuel and a passenger). In stock form, you'll find most R35 GT-R's making 400-430awhp for the 2010 model year (that's the year that I have). Certainly nothing to sneeze at, especially with the quoted 0-60 time of 3.5 which I have found to be extremely consistent (it's an 'automatic' remember). Pump a little bit of money into her, figure $4,000 if you do your own labor and this beast is quickly at the 550awhp mark (93oct, y-pipe, downpipes, tune, intake, 1000cc injectors) which turns the car into a high 10 second beast (just like in 'fast and the furious') - fast enough to embarrass almost anything on the road. Of course you can get really crazy and go with different turbos and supporting mods and beat up on 'busas on the highways but I'm not going to go there because of costs (figure another 15-30k depending on how crazy you want to get).
Purist seem to hate the GT-R because of the gear box, claiming "the car has no soul" as you effortlessly fly through a corner with instant shifts and practically point-and-shoot mentality. These fan boys associate the difficulty in driving a vehicle to how 'pure' a car is which to me is stupid. If technology progression is a bad thing, we wouldn't have cars with turbos or limited slip differentials or air conditioning while running down a track at 120mph on a 100 degree day. What a lot of these fan boys don't understand is that the GT-R's transmission *is* essentially a manual transmission that is computer controlled. Gear selection is a breeze and while there are some disconcerting noises when stopped or in slow traffic from the rear located tranny, it functions better than any human could control.
The GT-R was a completely different beast. Driving around town you get the stares and the attention of an uber-exotic. On the highway, in parking lots, basically anywhere you can find people, there will be people taking pictures of it. Car meets are even better with comments like "this is my dream car" or my personal favorite "why didn't you get a lambo or a ferrari instead". Ok, I know the second comment came from a guy that had no understanding to the cost of cars but the image was still there - that the GT-R possesses the same image as high end exotics on the road. Even people that know nothing about the car will approach and ask questions about it. It's always a new adventure being in public with the GT-R.
All in all, your decision to cross shop an M3 and a GT-R is purely an artificial one. The M3 is highly refined, overall luxury car with a little bit of pep when you need it while the GT-R is an attention grabbing performance beast. If I had to choose one car for a daily driver, it would be hands down the M3. But being that I'm young and reckless (owning a second vehicle helps too), I'll keep the GT-R in my stable for a long time.