Gravity Defyer shoes are intended for people with ankle, knee, hip and/or back problems, or who spend a lot of time on their feet.
I just got pair of their dress shoes, and they are awesome! The soles feel like very cushy sneakers. (The uppers are more like shoes.) I can only imagine what the sneakers are like.
The ones I got were probably a little generous, size-wise. My feet are between 9 and 9-1/2, and the 9’s are plenty big for me.
They have (3) springs in the heel for extra “bounce.” That’s the gravity defiance. It probably also means the bounce won’t disappear as it wears. They also have a very cushy insole that is “orthotic friendly” and works great with my Marathotics. If you have a full-foot orthotic, you might prefer to remove the insole, which is really easy. They come with a sub-insole you can use to select between wide (leave it) and normal (use it) width.
I’ve only worn them for one day. I can’t say I’ve experienced the “propels you forward” that the company claims, but I certainly had a good bounce in my step, especially for being sick and walking 2-3 miles, and my knees felt much better than I expected at the end. They have a lot of testimonials on their website. I find them pretty believable.
If I had any use for daily-wear sneakers now, I’d be all over this. And, yes, they really are crazy expensive normally. These are last year’s models and they have them on sale for $100, so it’s really a good deal here (I don’t say that so often).