Are “legit live rocks” worth it? Do they make your corals grow faster?
I prefer cycled dry rocks (faux live rocks?) since they are free of pests. Most my tanks have started with dry rocks so yes — brutal during the first year but stabilized afterwards. Guess I’ve never had true “legit” live rocks so can’t compare.
I think it's a matter of opinion and choice. For this next build, I'd like to go old school if possible and use natural rocks, both because I find them more aesthetically pleasing and I want to capture the diverse micro biome that bacteria in a bottle just can't match.
I used Marco rocks for my last build. I was very happy with them at the time, and it was very amusing to experiment with mortaring them together into structures. And they've been more than adequate in my tank, no complaints really. That said, in my opinion, they simply don't compare to natural reef rock. I have some old school Tongan branch rocks and they're my favorite rocks in the tank.
In my experience, real rock is vastly more porous such that, pound for pound, they occupy more space. I would presume that they offer vastly more space for both aerobic and anaerobic bacteria to colonize relative to synthetic rock. Further, they take to drilling a lot better than synthetic rock, which is nice for mounting plugs.
Will real reef rocks make corals grow faster? I don't know, I wouldn't think so. Will natural rocks kickstart the establishment of a solid reef tank? I think absolutely yes.
At this stage in the hobby for me personally, I'm more concerned with aesthetics than growth rates. And as a guy in his 40s, I have some nostalgia for live rock delivered in wet newspaper. I don't mind splurging a bit on this build.