[kdog26372]

RWD and xdrive will be close to the same in regards to 0-60 in stock form. In fact Car and Drive got a slightly better time with RWD vs. Xdrive version of our M235i even though BMW says should be .2 quicker. Could have been the weather that day who knows.

If you tune your car the xdrive on stock tires will be much quicker to 60 than the RWD w/LSD. The LSD really helps with powering out of corners, I found no noticeable difference in my 135i in term of straight-line acceleration after LSD install.

The 335 xdrive has a different suspension than the RWD version. This is not the case with the M235i, same suspension RWD or xdrive.

As will always be the case you need to drive both and see for yourself what you prefer. People on here with RWD will tell you the reason they chose/like that and vice versa with the xdrive folks.