Honestly talent tree seem like a dead idea in terms of MMO design. It's a wonderful concept but ends up being one spec to rule them all. Look at WoW, every xpac the devs try and change it only to players find the best spec and make all other obsolete. Even in it's current form they have to balance 3 different spec within the same job so one isn't superior. We have 17 job and if they only added two talent spec that would require 34 specs to balance. It's a lot of work.

Now look at our materia system and what is the most prized of the bunch for dps.