So how is the FFT style system different from the specialization system?

The FFT system has pros and cons like any other system would have, no system will work perfectly; people will find things they like and dislike about anything man-made. No system will be able to incorporate everything and make everyone happy.

Pros
-the “basic” classes/jobs are still viable choices; they are not longer just paths to some other end, they are an end in-and-of-themselves. At level 50 or 60 or 70, people will not just be GLD/PLD or GLD/DRK but will be either GLD or PLD or DRK (or all 3 if they want to level them all high).
For instance, PLD uses a block mechanic to tank and self heals using mana, while GLD uses a Parry mechanic and group buffs using CDs. So both are tanks, but do it in different ways and therefore have different flavours to them.

-Opens up more lore/player opportunities for the classes/jobs. With a specialization system, GLD are forced to become “holy warriors” or “dark warriors” (over-generalization of course). The quests and lore for the various “advanced” jobs can use the fact that players combine certain aspects from the basic classes to enter new frontiers of adventuring and form new ways of fighting. Which sounds better, a GLD who decides to suddenly become good or evil, or a character who realizes that he can enhance his fighting abilities with his sword and shield by adding elements of white magic to better protect his friends?

-Future proofs the game for new jobs in later expansions. There is no reason that later expansions can open “advanced advanced” jobs that require the player to have combinations of advanced jobs to open, i.e. in some future expansion, SE could release Star Mage, which requires ranks in BLM, RDM and time mage (all of which require their only ranks to be available.) This gives the games new branches and avenues of lore for future updates, i.e. some NPC is forced to defend a hamlet and accidentally combines two types of magic never tried before and opens a new element of magic or something.

Cons

- It requires a lot of revamp and expansion of the current game system, which in turn requires a lot of play-testing and trial and error. This will require a great commitment by the SE staff but also by the players to stand by while the staff works on the elements needed to implement this system.

-it would require a 180 on some of the lore and current understanding of the disciplines we currently have in game. The current jobs/classes we have will need to be redefined and given more specific roles, which eliminates some of the beauty and customization in the Armoury system.

I am sure there is a lot of stuff i have missed or not explained clearly, so please make comments and criticism so i can improve on it. I want FFXIV to be the great game i kno it can be, so if this thread in some minuscule way ends up helping that along, then it is more than worth the effort