That is true, there are unwanted hitchhikers, but look at the color. I thought I wanted the hitchhikers also but quickly decided the some of them weren't so keen.
My crabs molted in two weeks and balooned in size and were after my clowns pretty quickly. They went to a LFS
But the color, well, nothing like it, compare it to rock at a LFS
and there isn't much of a comparison.
I've got a clam of some kind that filter feeds, lots of purple corealine and some great porous structure to aquascape with.
We picked up some urchins on our rock, they remain in the tank at the moment. Some snails and small pistol shrimp tagged along also.
I'm going to introduce a Peppermint shrimp this week and he'll likely clean the rock up some from what I'm told. The aptasia is a little ugly but not terribly.