I agree, I have seen many different types of rock and I get what jumps out and says buy me. The Marshal Island rock is good looking rock from what I've seen, a little pricey, but has a lot of growth on it. The Fiji premium looks good as well, and the price is good right now, pretty much anywhere you go. Be a little careful about buying rock like Florida Aquacultured, it tends to be real heavy. There are not a lot of tiny holes for good de-nitrification.
Back to the Marshal Island rock, sources claim that it is actually dead coral heads and parts of the reef that have been overgrown with coralline and other cool algaes, sponges etc... claims to be very light compared to others, which means you get more for your $..Just my thoughts.