The Shimano SPD-L are just bloody dangerous seeing there's nothing to stop your foot sliding right off the front when you're trying to clip in (and miss). Not a problem with a freewheel where you can stop the wheel and pfaff about but with fixed gear and rigid, smooth soled, slippery shoes, I wrote them off as a bad joke. Something with a lip to catch the front of the cleat is much better (yes, I know, other brands do offer that).