Originally Posted by DallasBoosted
The larger master on the M3 will give you a little less pedal travel with the same BBK, but other than that as long as you don't run out of travel in the master cylinder, its kind of a feel issue.
My .02 is you will probably never notice the displacement difference so don't stress about it.
Thanks for the input, that clears it up a lot. How much of a hassle would it be to upgrade the master cylinder ?