Am thinking about putting them on my 200 and I am wondering if they are different in any other way apart from width, and if this would effect their efficiency on their respective discs?

The disks and calipers are the same apart from the thickness of the front disks (and hence the width of the opening on the front calipers) As the diameter is the same, the only difference I can see would be the rotors ability to dissapate heat would be marginally affected. The same size pad is acting on the same diameter disk. But i stand to be corrected, as always

Thanks, just wondering if there might have been some sort of internal difference in the caliper itself!