Gulf view rock was good, and you can feel like a responsible reefist when buying from them, because this is aqua-cultured rock. I got mine yesterday, and decided it best to cure the rock first. Great idea, right now my house smells like low tide in a sess pool. I checked the water parameters of the curing rock, I've never seen ammonia levels so high. Ammonia is 1.0, and nitrites are at .25. This would have killed the last two inhabitants of my tank.
If you buy online make sure to cure the rock first, if you have anything alive in your tank.