As others have noted, you really need to take the time to get these fitted properly. The first time I used them, they rubbed the back of my knee, but after I took the time to set them up, I used them for a weekend of BMX racing and didn't even notice them. I've been using THE knee/shin guards for a few years and generally liked them, but the strap above the knee was never long enough to go around my thigh and I didn't like having to take off my shoes to remove the pads.
From a looks standpoint, these are hot.
I'm 5'9'' and 170 lbs and use the L/XL. I think they could tweak the rear strap above the knee a bit (so it was softer) and they would be perfect.
Great shorts. I use them for BMX racing and love them. The sizing is right on,the length is perfect, and they look even better in person. I've used TLD shorts as well for years, and I'll be getting a few more pairs of these to round out my collection.