[fasternfaster]

There were some really great responses so far..

I had this same dilemma 2 years ago and i decided that the 15k difference in price was too much. I bought an '07 E90 6MT 335i fully loaded. I loved the car but over time the small things just started getting to me. The engine was too quiet so i swapped out the exhaust for a Borla turbo back setup and that improved things for a while. Then the run flats drove me mad so i swapped them for some new wheels and tires (19x9 and 19x11 with Bridgestone RE-11 235/275 widths) this made the grip and ride much better.

The car needed better shocks and an LSD badly.. Over certain bumps the ride was jarring and i thought there was nothing that can be done until i drove the M3 on the same bumps (more on that later). The lack of LSD really took the fun out of getting on the gas. Basically with 1 tire getting traction even with super sticky RE-11 275 width tires i was ALWAYS seeing the traction control light. With traction disabled i didnt have the confidence in the turns.

It seemed to me that to make things right with the car i would be spending upwards of 7k into a car that was not going to appreciate in value due to the mods. I decided to cut my losses and upgrade to an M3.

I bought an '08 E90 M3 2 months ago and owned both for a month until i sold the 335i. I was able to drive both back to back over the same roads on multiple occasions.

Here are my thoughts on the differences:

The throttle response on the M3 is insane! Slight throttle inputs or jamming the throttle to the floor all provide instant acceleration. Try doing that in a 335i.....and there is one big difference. If you quickly go WOT to no throttle back and forth a few times in a second in a 335i... NOTHING WILL HAPPEN! If you had a passenger they wouldn't even look at you. If you did this in an M3 in ANY gear even with its inferior torque figures, depending on the RPM it will either make your head wobble back and fourth or smack it against the head rest hard. I have a friend with a 2011 5.0 Mustang and he told me his car has more throttle lag compared to the M3. Also this car doesnt need an exhaust, its loud enough and sounds great stock.

Suspension, the EDC is awesome, its more taut than a 335i yet going over some big bumps that would almost feel like i was hitting the bump stops are no drama in the M3. Similarly some bumps i had to let of the gas in the 335 to avoid loosing traction whereas M3 goes over them with no issues.

Surprisingly the sport seats in the 335i fit me just as well as the M3 seats the added shoulder padding makes no difference for me.

Seeing the power dome each time you get in the car is awesome.The car looks much better in general and i always look back at it and smile, although i think i do this with all my cars.

Some negatives, in the 335i on my average commute i got 20-20.5mpg, on the same exact commute driving the same exact way in the M3 i get ~17mpg +/-2mpg depending on how much i beat on it.

Parts cost considerably more for the M3.. I did a full brake change Pads/Rotors on the 335 total parts cost was ~$550. Same parts for an M3 cost $1400. But you got to pay to play.

Bottom line, i dont regret selling my 335i at all! Only wish i could have kept the wheels i got for it but the offsets dont match what the M3 needs.