Off topic perhaps, and not making a comparison as I haven't driven either, but I am absolutely amazed at the reviews for M135. Must of read over 20 as I have a passing interest as my lease runs out in June.
Gets rave reviews. Certainly more than the 135, and possibly even more than the 1m. Journos love it.
Don't quite understand why. Surely a N55 135 with even a BMW PPK tune would match it in a straight line, and around corners with some basic upgrades