I have a professor whose favorite type of pedal is a round pedal that accepts a round cleat. The disengage mechanism is the same as other pedals, but he claimed the round pedal didn't strain his knees at all because of allowing his knees to rotate freely.

I know other pedals have a float adjustment, but I'm curious about what he uses.

How about Speedplay's?

.

Yup, sounds like Speedplay Frogs.

I was thinking either Zero's

or X-series

could possibly be bebops as well? Which is the best pedal, IMHO.