FWIW, you can ride on "clipless-only" pedals with regular shoes, at least if you're not going very far and you don't try to really hammer on them. I've ridden with sneakers on my Time RXS pedals. They were actually easier than using regular shoes on the Crank Brothers Quattro pedals I used to use on that bike; the CB's eggbeater mechanism wanted to roll my shoe off the pedal, while the RXS's plain, flat body is just merely smaller than a typical platform.