I agree with X5 Meister, 37K miles is no indication of whether or not the rotors will be within spec since we all drive differently and subject our vehicles to different conditions.

I have no problem with resurfacing rotors but in my experience BMW rotors are already thin to begin with and can be out of spec or borderline after resurfacing. The cost of new ones (or good OEM replacements) are not outrageous and IMO it's just easier to do the job right the first time than having to deal with rotor issues later.