I've used Sculpey and Super Sculpey. Neither are very durable though I find Super Sculpey never really properly hardens and while baked Sculpey is harder, it's also brittle. (T_T) So yeah, I probably wouldn't recommend them, even though they seem quite popular from what I've read in magazines. I guess they're good for making customising toys that you only ever intend to display and never play with... which does NOT work well with me!