I think FFXII had a lot of great ideas, but implemented them poorly.
The story was both good and bad to me. I loved the political aspects of it, and found the villains vey well rounded characters overall, especially the Judges. However, your party is of six were poorly made characters. The main character Vaan is actually not the main character at all, but more of a whiny sidekick. Basch and Ashe are the main characters of the story and they are merely a means to forward the political vehicle of the story. Nowhere in there do you feel at all attached to anyone's plight. Balthier had good comedic timing however. I'll give them that.
The gameplay was genius in thought but was handled badly. Like twestern perviously said, you don't get the option to update Gambits for sale at shops until certain storyline sections happen, but you usually require the skills way before you have the ability to buy the gambit for them. In some cases, with magic especially, I didn't get magic gambits in shops until almost 15 hours after having acquired magic for half of my characters, which is unacceptable. It took away from an otherwise killer system for grinding levels, as otherwise you could twirl the analog stick around with your eyes closed and have the game basically take care of the work if you undestood well enough how to properly gambit. Overall, it was a great fighting system marred by improper execution.
The graphics were vey well done, but the music didn't stand out to me.
One aspect of the game I really loved was the Hunts and the Thieves Guild surrounding it. I had the most fun hunting creatures that in many cases were well beyond my reach.
Another great aspect was your ability to basically travel beyond your levels and get clobbered or barely survive fights in high powered areas. It allowed leveling up to speed up and let you get your hands on some nice items you shouldn't have had yet.
The weapon selection was fantastic even if most kinds of weapons weren't very different from eachother when it came down to actual gameplay.
The license system was horrible. It's basically a checkerboard with mystery tiles, like Smash Bros. Brawl's Achievements where one tile will show what's in the surrounding tiles and so forth. You couldn't use any accessory, weapon, armor, or summon monster in the game until you purchased the license for it. Unfortunately you very often need to purchase unnecessary licenses to get to the ones you want.
As for my RPG background, i've played FF 6-8 and 10, Vagrant Story, some Chrono Trigger, Persona 2, Growlancer Generations, Arc the Lad, Tales of Symphonia and a few others but mostly enjoy Turn Based Strategy RPGs like Disgaea, Fire Emblem, and FF Tactics. I'm also playing through Planescape Torment, Jade Empire and Fallout on the other side of the RPG spectrum.
I don't know what your history with RPGs is, but for the relatively cheap price, you might as well jump in. Maybe give it a quick rental just to try it out before you decide. This is one game I wouldn't trust the high review average with. Reviewers were very lenient with this game, and I don't feel many of them really played too far into it.