I put these on walls of various angles to see how challenging they would be to hang onto. Overall they feel a little easier to hang onto than a typical modular hold. They are not too difficult to hang onto on a vertical wall, but are quite a challenge for even small overhangs. I can use them on a 50 degree overhang with a great deal of effort, and I feel like I might be able to one day make use of one or two on a ceiling; that's something I can train towards.
They're a novel challenge that feel a little different than just about anything else I've encountered on a climbing wall.