I know I'm behind the curve, but the demo is still addictive, if played every once in awhile. I love restarting the last part once I finish the thugs, I like trying out different strategies.
One of them is to pull a Naked Snake and just sneak around. I am 1-0 for this style, but it is one of the least satisfying. The cons of gargoyle hopping (feeling cheap) can't beat out the pros (moves like glide kick, hang, inverted takedown, taking out a thug with a thug you hung before). I particularly hate swinging to a gargoyle, and even though I almost smacked a dude in the face with the end of my cape, he doesn't notice. WTF???
Another I have been using more often, is using the gargoyles, but not the x-ray vision. Like many reviews have stated, I think it takes away from all the hard work the artists and animators put into the game. But it does make the riddler things easier to find. I found the one at the beginning of the demo just today by turning it on after I took out the 2nd wave of goons. Back to the style, I like it because, again, it doesn't make me look cheap. Yet it is still exciting, because I can use all the gargoyle related moves.
Using Batman's entire arsenal is awesome, no need to explain why. But it makes Bruce a bit too godly, since he knows where everyone is, and also how scared they are.
One I just tried to mix it up is the "loud" style. Gargoyles and batarangs are ok, but no silent takedowns, and no ground takedowns. I like stealth so I'd never try this otherwise, but I just wanted to see if I could get a perfect in 3 tries. That was a HELL NO. It takes way too many hits to take out an enemy, but it's sure as hell fun to try, you feel like Rambo.

t: I'm gonna experiment in a bit how many glide kicks to the face equal a KO. I'm putting money on 4.
Oh, and I have some questions for those who have beaten the game.
1) Do the thugs become more aware as the game goes on, or at least on the harder difficulties? When it comes to Bats swinging around like he's starring in Bionic Commando, I mean.
2) Is the combat way more satisfying when the lightning bolts are turned off, and are they optional on the easier difficulties?
3) Is the final boss really as lame as GI says?
4) I am the playing the demo right now, and for the first time, I took out one guy loudly and the other 4 got into a "squad", thus checking me for a solid couple minutes. But eventually I just decided to glide kick in and break some jaws. I got shot up, but nothing is more epic than swooping in on 4 guys with AKs, and actually winning. Except not getting hit and doing that.

My question is, are the routes of the thugs dynamic like the one guy said in the first predator challenge video?
5) Is a gargoyle-free walkthrough possible? If not, does the stealth mostly feel strategic, and not cheap, since Batman can pop back up the the ceiling and move to the other side of the room if he gets in trouble? Maybe the garoyles aren't so generous in the actual game?
6) Without searching for Riddlers' clues, how long is the first playthrough? With?
7) What is the # of alternate costumes that come with AA, if you didn't pre-order?
5) A sequel that is similar in concept but set in a new area sounds like gold, but if it could be guaranteed that a polished, AC2-type game could also be made (90% of missions would be indoors, Batmobile/Batcycle/Batboat would be available, Gotham would be as big as SM2 NYC), what would you choose? I would have to choose the latter, since they could copy and paste the gameplay from the first, and then maybe whoo some key members of the GTA development team so the open-world aspect would work just as well.