I have Candys, and occasionally ride in "normal" shoes. You can definitely feel the springs, but depending on the tread of your shoes they may be good traction (for big burly treads) or provide some good grip (with thin-soled shoes).

My husband wanted pedals that he could use with both cycling shoes and normal shoes, so he has a pair of Mallets. I don't think he's used them with normal shoes yet, but with the huge platform it shouldn't be too difficult.