I believe reef cleaners dry rock is just limestone, which looks alright but it isnt as porous meaning less surface area and less beneficial bacteria. It also isnt easy to shape like other dry rock like pukani
Reefcleaners, Marco, and BRS Reefsaver are all the same. They are mined in Florida....I purchased a little of all three recently for my current build, other than the flat bottom cuts from Marco, the rock is indistinguishable. You can see the photos on my build thread (link in my signature).