if your only asking the question what is more reliable. i would assume that a stock motor is always going to be more reliable than one with aftermarket FI on it....
im currently doing a s54 swap into my sedan that started as a 328i.. It deffinitly would have been a more difficult for me to choose the route i wanted to go in if i started with a 330.
that said, ill be very happy when i have a 350 hp N/A 6 cylinder engine under the hood of my e46 sedan. and now there is the option to add FI to the S54 and we have all seen what that is capable of.
the best option with the least expense for the ammount of benefit you will get is to just buy a e46 m3...
Last edited by BDUB328I; 01-12-2013 at 06:40 PM.