Too easy, not stable
I have a normal GHD, but my old gym has one of these. The rolling pads make this extremely easy and also decrease the stability, and not in a good way. I'm not sure why this is more expensive than other GHD's, but it's definitely not worth it. If you're too weak to use a regular GHD, just wrap a band around your feet (one at a time) and do hamstring curls with that. Alternatively, buy a plate loaded hamstring curl machine.