I'm not terribly surprised to learn that the M2 will be delivered with a four cylinder. Remember, the very first M car had a four cylinder. I am really in love with the sound of the engine in my current 135i, but I'd trade it in for turn-in sharpness that rivals a Porsche, which is only possible if you get the weight down.
2010 135i - TiAg Coral Red 6MT ///M-Sport
2013 X3 28i - N20 Mineral Silver / Sand Beige / Premium, Tech