I've been wondering about the disks too. I have some furniture movers but they are cracked on the bottom and I saw the Gold's Gym ones at Walmart a few days ago so I picked them up. When I got them home, it is apparent that someone had tried them and returned and I found out why, they just don't slide well. They are flat on the bottom just like the furniture sliders so I can't figure out why they don't work. I'm was using them on carpet for mountain climbers and they would slide then all of a sudden stop before my leg was fully extended, it's aggravating. I'm going to try them on a different carpet tomorrow but I have a feeling they are going back. The thing I don't like about furniture sliders is the foam on mine is kinda high so I feel it's harder to put my heels down to stop; but they do slide well. I've been working out barefoot, maybe if I used shoes with them that'd help.
Does anyone use the slide & glide disks barefoot? It looked to me like there is a lip around them or partially around so I was wondering if they are comfortable to use without shoes.