while materia did certainly become a very addaptive medium, i still dont feel it's teh best if anything because of the time and effort needed to train all your materia up to level three etc, with the junction and aeons you simply choose specific talents to learn and get ultra powerful magic instantly. that said the dressphere system could decimate the materia system easily.

not only do you take into account the inhernt abilites of the many dresspheres, but the truck loads of differnt garment grids which have varying kick arse bonus. decreasing any magical attacks, while absorbing magical attacks, reflecting them while building your stragth, giving you teh abilities of a black mage while being in the powerfully immune stance of a darknight...and if anytthing gives you trouble, catnip with trigger happy