I just picked up the 16 f1.4 and am looking for a clear filter, just for protection. I've always used the B&W XS-Pro MRC-Nano 007 filters in the past but the 67mm size is a bit expensive. The XS-Pro MRC-Nano 007 is $49.95 and the XS-Pro MRC 007M is $32.10. It appears the only difference is the Nano coating which promotes beading of water for easier cleaning. Does anyone have experience with the non-Nano coated version? Are there any other differences between the two?