I remember when Look first came out with clipless pedals. Up until then everyone who was into performance used clips, cleats and straps. While everyone seems to be talking about the benefits of the power on the up stroke there is also the back stroke which is the advantage cleats gave over simply using toe clips and straps. Before you stopped you had to reach down and loosen the straps so you could get your foot out. Clipless were a great advance and became popular rather quickly. They were not a performance enhancement over cleats and straps but they were a major convenience advance. The only time I've ever fallen with clipless was when some idiot who didn't know how to work his pulled up next to me at a light and proceeded to knock me over when he had trouble getting out of his clipless pedals.