With over 40 years of scientific observations and evaluations I concluded that surface area and relief are the two most important factors for success. Reef Balls have the best surface area and provide relief that has the best resilience for restoration projects. Plus, the formula for Reef Balls is inert, other products do not provide a structure suitable for as wide a spectrum of marine organisms. Until I find a better material I suggest using nothing else. 23 years of successes, and pages of scientific research provide the proof.
J W McFarlane