Having played at release till about 4 months in - No don't buy it.
From reading up on the game just a few weeks ago - still not worth buying.
-The game looks beautiful but the engine runs it horribly.
-The "world" is tiny, most zones are very thin corridors.
-The crafting system is massively convoluted and while is purposely complex, the lack of information on it made those "learning" it very frustrated. It has been simplified to some extent, but when it comes down to it, unless you devote your entire game time to crafting you cannot do well. Crafting is a class on it's own, but its not fun. As well, many crafting recipes would required ingredients made by a higher level craft skill level.
-Combat is awful. Bad. Terrible. Boring. It was advertised as an "active" system with "no auto attack", but in reality, you use up your energy/mana and then rely on what is essentially an auto-attack, except you have to constantly click it. A recent update actually added auto-attack, and revamped the system slightly, but it's still boring as hell. That being said, its no different than most of other mmo's. The exception is that it doesn't have the depth that FF11's did, or if it does, it is currently broken (the combo's or whatever they were called that allowed for additional attacks)
-Statistics are borked. Some statistics have such a little effect on your player or skills that there is no point in using them. What is a 5 (or is it 6?) stat game boils down to 2 stats, and those are limited by your level, so you eventually have to "throw them away" in those other broken stats.
-Equipment has huge disparities in usefulness and level. A level 15 item might be found at level 5, and by the time you are high enough to use it, it would be worthless. You could also equip items that outleveled you, but at a huge penalty stat wise, this was needed at times though, as items were so limited that you'd be level 13 using a level 5 wand or something because the only other one that existed was a level 16 wand. Repairing items is expensive, wearing outleveled items break faster, items themselves break extremely fast.
-The quests and "leves" as they are called are sparse, repetitive and sometimes broken. "Leves" are what you would consider "quests" in most games, except you're limited to the amount you can do on a daily basis. This would be ok if "quests" weren't actually "class progression quests" and only come every few levels (every 5). Which means that you literally can only do ~10 leves a day then grind grind grind, which in itself has a daily/weekly limit on the amount you can gain until you hit dimishing returns (this may have changed now, but from what I've heard it still exists in some form).
-Many advertised features still don't exist. Every town has chocobo stables, but no chocobos exist in the game as a mode of transportation. This doesn't really matter though because as I mentioned before, the game is woefully tiny in comparison to most MMO's.
-The game is just now putting out instanced content that is completeable. Previously zones existed, but you had no reason to go and even named mobs had no extra rewards for taking them down.
-Mob levels / aggro colors have zero correlation to their danger. There are huge discrepancies in mobs in the world. A level 30 mob that cons green to you could 1shot you. Some mobs like these are in tiny corridors directly adjacent to the mobs you need to grind to level up.
-And the game is buggy all around in general.
The upside is that it is still free to play since Sony acknowledges how broken the game is.
But it's just NOT fun.
I am jaded. I am cynical.