I see videos but I still can't get a mental grasp of it. How fun is it? And does it get stale? I need to know this because the game does look really interesting.

It's marvelous. It's hard to master, as you have to look a fine way to combine your arts (they're like special attacks), and you have to pay attention to all your party's arts too. Also, you have to watch out your position, for example, you will deal more critics if you're behind the enemy, and some arts have some special effects depending on your position. It gets stale if you want, because you can change class in the middle of the game if you're getting bored. I think it's one, if not the best way to combine both turn based combat with real time combat.

Interesting... Can you dodge? And how different is mech combat?

Nah, it's similar to the combat system of a MMORPG like WoW. You have a cooldown for your arts, but not a way to dodge. It's, like I said, a mixture between turn based system and real time. Well, the main difference to me is that on foot your arts are dependant on your class, while with mechas, this depends on the weapon you buy. Each weapon has its art asigned, so you can make a lot of combinations building your skell. 

Oh, so your incentive for moving around is to get crits on the enemy's back? I'm definitely getting this game, even if its to see what this gameplay style is about.

There is no way to dodge, however there is an evasion rate and attacks can miss. I am not sure if people still do that in X, but in the original game people would equip Agility on a character called Dunban, so his dodge rate increases significantly and he becomes an amazing tank. I think you can still do that here.

You also move around to switch between ranged and melee attacks.

Mechs are just like on foot only way more epic and ur Arts(skills) depend on the weapons u equip. I think the maximum number of weapons on a Mech is 10 ranging from ligh sabers to missles

Mech combat sound hype as fuck! :O

Watching videos of it had me confused, I couldn't grasp it either. It's really good and different, as others pointed out a mixture between turn based and real time.

The game also allows you to change classes as you see fit, I had fun with a few of them. My favorites being Samurai Gunner and Blast Fencer.

I think a lot of it will depend on how much effort you're willing to put into learn it, and I mean that in the least condescending way possible. For me, X's combat has been a chore up to this point (I'm on chapter 6 currently), and a lot of that has to do with the fact that the combat is based less on things like reaction time and avoiding attacks and more on just keeping track of what your various arts do, where they're most effective, when to use them, and how to use them in conjunction with the rest of your team.

The game doesn't really explain this beyond a simple "make sure you're not just spamming your arts mindlessly" prompt at one point, and I've gotten along just fine without putting too much thought into things (at least, not counting the times when the odd level 50 enemy spotted me), so it's something you'll probably have to put a concerted effort into learning. The game doesn't really force you to learn the ins and outs of its system, and there doesn't seem to be a real tutorial for it, so the initiative will be all on you.

Fresh. When you get the Doll - pure fun.