Pedals are one of those interesting areas of the bike that haven’t changed all that much since LOOK introduced their clipless prototypes back in the 1980s.
Yes, brands like Time and Speedplay have taken the idea in a different direction but – on the road at least – the fundamental ‘press down with your foot to engage, twist sideways to release’ mechanism has remained the same.
Shimano are a big player in the pedal market. Part of their appeal is the uniformity of their pedals. Regardless of whether you go for the budget R540s or the range-topping Dura-Ace 9000 pedals, you get essentially the same mechanism unlike, say, LOOK where it changes from a spring to a carbon blade as you go further up the range.