FFXII lives up to just about all the standards of FF, but doesn't really exceed any of them. The biggest change of course is the new battle system. It isn't exactly turn based anymore, but it isn't exactly real time either. You're dudes still have to wait for their attack bars to fill up, but you don't have to just sit there and watch them look dumb while they do. You're always free to run around and go where you like even while in battle. The main advantage to this is if you want to have defensive characters who use magic, you can keep them away from all the mayhem and have them blast from far away, while you're melee dudes run up and beat the crap out of the enemy. It adds a new level of strategy to the combat portion of FF.
One moderate gripe I had about FFXII was the quickening system. This is what replaces the Limit Break system and it's kind of lame. My main gripe with them is that you don't really have a way to make the strikes more powerful, like in FF8 when you could time Squall's attacks right to make his Gunblade shoot. You can link your characters quickenings together which gives some kind of player interaction but it only requires a single button press to do which isn't really that fun. Also the quickenings do not have to be built up by being hit, they only require mana, which means you can pretty much use them as much as you like, and in turn it kind of takes away from the rewarding feeling of getting a Limit Break.
The graphics rule. They always have in FF and this one is no different. The CG's are especially good. Watching the Archadian Army go to war in Dalmasca is unbelievable. I don't have single complaint about the graphics in FFXII. Everything from the in game combat to the quickenings looks great. Nuff said.
As far as the story goes in FFXII, it's much more adult oriented. The theme is more grown up and the plot is more serious than the others. This is a story about nations going to war, people dying, and princesses taking their own lives. It is almost like a novel. The city of Dalmasca is under Imperial rule and the citizens are upset, around every corner there are guards bullying and bossing the citizens like slaves. It is a story about gaining independence and freedom, and to restore the rightful rulers of a city in despair. It's definitely a deep story worthy of FF.
I think this is a great game for any RPG lovers and FF fans. Even if you didn't like other RPG's before, I think this one deserves a try. The new combat system may be able to sway you over to the RPG world. It's a game with a great story, excellent graphics, and a deep enough character development system to keep you playing for months. FFXII gets an A- .