i WOULDNT SAY fIGI IS the best bio filtration,, nor would i say it looks the best. I do know it is very common, and relativley cheap. Probably the cheapest, but im not saying bad.
When choosing LR,, you want to consider the density of the rock and usually want porouse rock, meaning little holes all over the rock. This is good because the water circulates better in an aquarium. I personally have nambu LR and branch rock... Perfect for my FOWLR tank because water is constantly moving throughout the tank and can circulate, which doesnt leave me with many DEAD spots. Hope this helps,,, BYE