I've been told by many people to go clipless, but never really had anyone explain why. Before I forget, here it is-- power and balance.
Pedaling power is much greater. I am cruising at 3-5 mph over hills that I recently would barely make it to the top on at 1 mph. Think of an old steam engine. You know how the rod is turning the wheel all the way around, that is how you pedal. Your leg turns the pedal all the way around.
My balance has also improved greatly in a short time. If you know Sunderbruch, there is a 1/4 mile stretch of grass at the top with a well worn path. I was always bouncing off the walls of this rut. Now I actually can ride in the center.
It's also nice to be able lift the bike with your feet and not worry about if your going to land on your pedals or not, but is sucks being stuck to the bike in a crash.
I still don't understand why it's called "clipless" when you are "clipped in."
If you've been thinking about the transition, it is well worth it.