Tim,
Like all answers, it depends. If you find a place where you can let the screw dig in, it can be OK. Many places however do not have much sand/gravel/soil covering a layer of sandstone. In a good blow, and there are some dusie's there, they could pull loose.
I prefer a Fortress type anchor (x2 at least) that is up the beach and buried in the sand to a screw in type tie off. I also carry a couple of lengths of chain and carabiners to loop around roots, trees, rocks, etc. I think we have three anchor rodes on the boat, all with chain.
Steve