These things are great. Yes, they're overpriced for what they are, but for 10 bucks, buy it once, install it, adjust it, and then never have to screw with your trem again if you want it blocked.
Technically the trem is dive only with this, but for my guitars that use them I toss several extra turns on the claw and then throw an extra spring (or two) on the trem to really pull the hell out of the block into the stop. Works great and I've never had a problem.
I use these, too. They work as advertised, and no screwing around with finding the right size shim to make trems dive-only.