I had to return this particuliar model cause it was too large. I own 3 pairs of Amps cause I got them half price from Big 5. The Amp (to me) seems a little more cushioned to run on concrete, I live in LA. I would have re-ordered in size 10's I wear the 10 1/2 in the Amps. Read mixed reviews size wise for the Slides (some say order smaller...larger) went with larger, wrong. Wanted to really give this shoe a shot, but I have enough Skele-Toes for now. I use for running, tai-chi, light weight work, and calisthetics. I am a hardcore fitness person that has 2 metal hips, both knees have meniscus tear.  I have used Nike Pegasus forever and always thought that was the best training shoe regardless of price. THIS is the best!  A running shoe regardless of how light still has a thick striking area, until my hip surgeries all foot strikes felt fine.  After the surgeries, my foot plants felt awkward, painful jolt to hips, and uncomfortable. RUNNING was no longer an option.
About 2 months ago I saw the Skele-Toes on sale and decided what the heck. I tested walking and light jogging they felt fine! Then took a shot at my 20 minute interval bike routine with running. 3 min. warm-up, 30 sec (100%) sprint, 1 1/2 minute recoup, 8X, then 2 1/2 minute recoup, total 20 minutes. My legs and feet felt great and that has sold me on these shoes foeever!  I have endorsed them to all my freinds, I hope this helps people who may have doubts to check them out...these shoes deserve serious consideration!  ADDENDUM: I have worn orthodics for the past 30 years, I don't wear them with these guys and have had NO ISSUES, there is something to be said for the idea of barefoot running (if you live next to the beach run on the sand), this is as barefoot as I'll ever get, cause if you're "crazy" enough to run barefoot in the concrete streets...more power to you, not this guy!