Can't say I've been in the mud, but one of the trails I ride the most is paved with crushed gravel which get's pretty nasty when it get's wet. I know they have help up to this stuff pretty well and it's really more like a cement or plaster type mixture when it gets wet. I ride the trail even in the rain so suspect they will hold up pretty well to mud. If they get too gunked up shoot them with your water bottle!! Didn't pay attention to your CDN so your probably right in the ball-park. I usually hose stuff off after a ride and dab them with a little grease to keep them clicking happy. I would have expected them to flip with the cage down, clip up, but have not found that they land either side up on a consistent basis so they seem to be pretty well balanced. I clip in right side before I take off, and flip the left if I need to once I am moving. After reading all the folks with their clipless falls, I (knock on wood) count myself lucky not to be in the fallen group. It is weird when you come to a stop since for whatever reason I always end up leaning toward the side that's clipped in and have nearly fallen a couple times at a stand still. Have learned to pay attention and purposely lean the other way, and consistently leave my right foot clipped in for the duration even when stopping. GOOD LUCK on your quest. I have no doubt they will hold up for a year or two, just flush them and grease them when they get too nasty!