MrBubbles conducted a side by side comparison of the 2 demos and has decided to share his findings. 

MrBubbles determined that both versions were equal in a number of ways.  Both versions loaded the same, both ran the same, and both were texturally equal. 

However the enhancements on the PS3 version were glaringly obvious.  It contained not only enhanced screen tearing, but enhanced jagginess as well.  It only barely edged out in the jagginess department (it was far closer than what i noticed in the Bioshock vs Bioshock).  But it completely blew its opponent out of the water with its screen tearing.  The difference was severe, to say the least.

MrBubbles doesnt personally like the game ...but if you you are interested in this game and own both systems.... If these enhancements dont appeal to you, you would do well to pick up the Xbox360 version of the game.

Edit: 

Q1: MrBubbles why have you chosen to write your post like this?

A1: The owner of the PS3 suggested that it be written like this.

Q2:  But MrBubbles, i didnt see any screen tearing in my PS3 version of the demo...?

A2:  You are not alone, when initially playing through a demo most people are excited about playing their game and focus more about how something plays and if it is enjoyable.  If you play through a second time now, knowing that this occurs, you should be able to see it quite clearly.

Q3:  WTF MRBUBBLES R LYIn!!!111! HE juST HatEZ SONY!!!

A3:  Please stay out of my thread and take your trollish comments with you.  Have A Nice Day!

Q4:  MrBubbles, i know that the settings i use with my tv can sometimes have an effect on screen tearing.  I have had a number of screen tearing issues with other PS3 games and by changing my settings i was able to reduce my problems.  Is it possible that altering your settings could produce a noticeable improvement?

A4:  I have played a lot of other PS3 games on my tv and have never encountered screen tearing problems, such as these.  I am sorry to hear you have had so many problems in the past, but i find it unlikely that is a similar situation.  Although i will be willing to even test it out on multiple tvs next time it is in my possession.

I don't get it? Is this an attempt of being funny? Are you saying that jaggies are a good thing? Or do you mean the PS3 has less jaggies?

erm......?

The owner of the ps3 suggested i post a comparison worded like this.

Mr Bubbles wants to be funny... Mr Bubbles is partially successful, but in the same time fails :P

 Ah, yes, now that I know who came up with the idea, I can work out what is meant by it.

noob

And before people takes his opinion serious, this is the guy who predicted 16 million ps3 sold LTD after the holyday season......

so were getting more third-person speakers now?

 I dunno, I've only played the PS3 version... and it is pretty damned jaggy.