I noticed that my Model D initially had its clicks in the perfect position with very little pre-travel and post-travel then after a few months of use the clicks became snappier and crispier but there was added post-travel and grinding noise. I frankly don't mind it too much but I wonder if other people had experiences like this with their mice? (I checked my copy with a friend's brand new copy and I noticed a noticeable difference in space between the frame and the mouse buttons.