I'm about twenty hours in and I like it. Unsure where I'd rank it though. The graphics are well tasty and it feels like a huge amount of effort went on crafting the story and all the different personalities involved. Based on those alone I'd rank this (so far) as the best FF after 7.
However the game's really stingy with save points, gil, weapons and accessories such that you don't see anything like the continual improvement that you do in other RPGs. There hasn't been any other game where I've been stuck with the same equipment for so long. Most of the character improvement comes from tedious hours of levelling up your stats. The licensing system blows.
There's no specialisation to speak of and all the characters end up being capable of doing the same things. FF8 somewhat suffered from that but the different Limit Breaks partially made up for that. Most of the time I spend my license points on stuff like Black Magic 5 which I'm hours off from getting. Offensive magic really sucks. I'm still stuck using Fire, Thunder and Blizzard and I'm twenty bloody hours in! Apart from using Cure\Cura, sticking Protect on occasionally and removing status effects to save buying things like Eye Drops, I'm mostly just using melee attacks.
The lack of specialisation really hurts the fun you could get from the game. In FF6, Chrono Trigger and FF9 the specialised skills of each character made party selection quite strategic and allowed for a variety of different ways to take down bosses. FF10 had this and supplemented it by allowing you to switch members in and out, thus allowing you to bring in Auron to destroy enemy defences, drafting in Lulu to blitz it with magic and then Yuna to heal everyone. The materia system in FF7 allowed for hours of fine-tuning. Every new accessory, armour and weapon you got, allowed you to optimise your party for offensive damage, materia growth, healing etc. and got you to think strategically.
What really does piss me off is the lack of save points. I'm being forced to rely on faqs on boss battles because I'm not going to slog through a long and tedious set of dungeons for another two hours because I didn't buy any Hankerchiefs for fighting Belias.
All those elements I'd rank as being only a bit better than the woeful dress-sphere system of FF X-2. So right now I'd rank FF12 slightly below FF8. In part also because your summons are terribly weedy and quickenings suck ass. You have to go through some finicky chaining to do any appreciable damage and they reduce your MP to zero making them a bit useless for boss battles.
How I rank the FFs