I wasn't thrilled with Power Grips. Of course I tried them after having been clip-less for years.

I can tell you that I had two "incidents" in the last ten days on my mountain bike. I did not stay attached to the bike for either one. I use Crank Bros. Eggbeaters.

I formerly had SPDs and was quite happy with them. A double sided pedal is a nice way to go. It is what I use on my commute bike.

V.