Debuted at the 2017 Reef Aquarium show circuit, Two Little Fishies' STAX Dry Rock is a great option for marine aquascapers. STAX is a flat, porous, oolitic limestone that has been cut for ease of stacking.
Very decent rocks for quality, they are porous and probably the easiest rocks to chisel and work with (but always embrace that there's going to be some breakage-It's just the nature of the beast). They are also consistently very flat, something I did not find with Marco Rocks, thus making it easier to stack, hence the name. Aqua Lab is the real star here in that they let you select the sizes you want to work with. I don't think any other retailers do that. With very limited experience I was able to construct a half decent looking aquascape from it.