The first thing I noticed about the ED-500 is that they look more like a traditional pedal, and they use the same cleats that I already have. The other thing is that they are billed as a "light-action" pedal which I take to mean that they you don't need to exert so much effort to getting clipped in or out. I'm thinking lighter action could mean quicker release, which could be a little safer in some circumstances. Still, I'd be concerned about how well they stay clipped in as I go charging uphill at blinding speeds. (I wish)