Wow, it's been a while since I played FFXII. This kinda makes me want to play again, but I've got KH2 on its way to me, and hopefully FFX-2 in the next couple days, and that should satisfy my RPG craving.
I love the prince's armor (I forgot his name, sue me). If I had the money I'd have it made for me, and it'd be sweet if I could get my girlfriend to be Ashe.
Rabid-Echidna
Yiazmat is a whore.
Getting 100% in FF12 is significantly more difficult than doing so in any other Final Fantasy, depending on your definition. Getting all the best weapons will probably require something like an additional 50 hours of gameplay even after you've already done everything significant, and that's provided things go well. I spent about 5 hours hunting the one enemy required to get one of the three materials needed to construct one of the three main materials needed to get the best sword in the game. After a while you just declare that doing so is stupid and give up. I just settled for the Zodiac Spear, Excalibur and Masamune.
Summons are only good if you want to watch something flashy, but they die in about a second when fighting anything with a bit of power. The only one I ever summon anymore is Chaos, only because of awesomeness. Look up the Henne Mines training strategy if you want to level all your characters fast and do some real damage.
I've got everyone at level 99 with ultimate weapons and I've still never killed Yiazmat because of some lame glitch. You're supposed to be able to run out of the battle periodically to heal, since there's no way to kill himself without doing so. Too bad the game is buggy and he starts recovering a million health every second when you do it. It seems to be kind of random whether or not he does it. After fighting the fucker for 3 hours you lose the will to go back in after he's recovered to half health for no reason when he was just about to die.
PureLionHeart
Sorry for getting back to you so late.
I'm not sure how far I'll go with FFXII just yet, but I've yet to miss any weapons or anything that involve a one-time shot, and I have the some materials prepped for the Sunflower.
And I've ALWAYS found the Espers useless, with the exception of Zalera thanks to his Kill technique. I noticed the levelling trick in Henne, though. After some hunts, that's my next stop.
As for Yiazmat, I think it should be quite an experience if nothing else. Never fought such a long battle before. By the by, the reason he regains all that health is because he's casting Regan on himself, restoring like 500k every 10 seconds or so. You have to dispel him of it.
This isn't as hard or tiring as other games so far. FFX, FFVII and FFVIII were more annoying to 100% due to stat maxing, but as I understand it, this game has no such option, so I think I can put up with some annoying loot farming.