I've had one since launch. It's pretty legit. There are two mechanisms on the bottom that fit into that recessed portion of the PS4's frame, and once you twist to lock it, it expands the rubber feet into the groove to lock it in place. No issues at all. The footprint makes it a bit wider, and seeing as I have cats, I'd like to do what I can to keep it upright and not get knocked over by one of them. Thankfully, nothing yet.
OP, considering it's usually $20, I'd say this is a great deal (60% off).