I've got Shimano m50s on a road bike. I'm about to go clipless on the singlespeed, but I want to make sure that I can swap shoes from bike to bike. Will Performance-brand SPD-compatible pedals take the same cleats as the Shimanos? I guess it's out of the question that I ever switch to Speedplay pedals, now that I'm about to extend even further into the Shimano family....

The dumb short question: Do SPD cleats that work with Shimano pedals work with Shimano knockoffs?