I've been using them for over 10 years (original, X2 and ti versions) with good results until last fall...when I had a fall. I had one unclip while cornering. This has happend to me before on rare occasion but this time it led to a crash. I can't completely write it off to the pedals as operator error had something to do with it.

After my experience I did some investigation and found that most of the pros that use them opt for the Zeros as they are a little more stable in such situations. I will likely do the same soon.