If I think of all the tanks I've seen up close that have had substitute rock, none of them looked nearly as good as tanks with real rock. Not to knock anyone's methods (check out my glass house), but the more I see and learn the more I think that quality live rock is indispensible.
And for base rock, the closest to the real thing we can find - also indispensible.
JMO, but when you've seen enough DIY rock tanks with serious ugly problems, or even borderline ugly, you tend to get nervous. Try to emulate the best tanks you've ever seen...
(AS to free shipping from J&L, check the fine print: "*Does not apply to salt, chiller, aquarium, sump, or sand orders." They might include Reef Rock with sand...)
