I just want to add that, when I am descending at high speed speeds and making sharp right angle turns at 45 mph I need pedal retention. When I do corners like that it's not uncommon for me to see lean angles that approach 50 degrees. When I got my clipless pedals, I instantly found that I could hold a tighter line and climb better.

One more thing: A time or two, while descending, I have entered a corner and turned in too late, or with too much speed for the line I took. As a result, the bike has veered onto the unpaved shoulder. Suddenly, I'm being tossed around like a ragdoll, holding on for dear life until it's smooth enough to slow down safely or I can ease the bike back on the road. In those instances, I guarantee you, I would have crashed in a horrendous fashion if the pedals didn't keep me on the bike. But, because they did, I didn't crash at all.