I'm risk averse when spending money and not the best with heel toe, so for me it would be the new Nismo with srm. That being said, I did test drive a 11 M3 and a 12Z back to back before ordering my Z. I gotta say that the M3 performance was definitely superior and if it wasn't for that damn $28K difference at the time, I'd be in one today. Good luck to you OP