I have walked on rocky/shelly beaches, concrete, grass, you name it in these, and have found they perform equally well in all. could not have had any think better for the makers of the rest of air buds it still had us on the edge o our seats and it takes you out of the realy world for a while and that is a good thing The charging section snapped off from itself on both of them, so I would say that it is not at all durable. This bike stand was exactly what we needed to hold up our granddaughters bike. And now I?m left with ruined boots with dried up glue seeping from the soles, along with the task of trying to scrub off the dried glue from my countertops, phone, and manicure. and read about them. Im 58" and about 145 lbs and I got a large, and they are a perfect fit. I wish this company had sweat shaper yoga pants. The back of the slipper helps prevent them from falling off on stairs, and the tread grips quite well. It can make shoe fitting challenging.