I got Power Grips about two weeks ago. I went clipless this spring and they slowly destroyed my feet. Maybe the shoes were too small, but I can't afford to put out $100 here and there until I find the right shoe. So I went back to my old platform pedals.

Then I figured I could do better with clips or Power Grips. First tried clips, but they mash my toes and are too hard to get in and out of. They probably would work better if I had thinner soled shoes, but then I'm back to getting new shoes. And a type they don't seem to make any more. So I've had the Power Grips for two weeks and my feet don't hurt so much anymore.

nowheels, I'm guessing your pedals had a serrated edge that doesn't allow much float. They don't seem to help keep your foot from sliding off, but then they probably got a good write up so that's what they got to manufacture. I switched to a smooth pedal and my knee pain went away.