Uzgull

I am going to download the demo later this week and was thinking about which class to play, shaper, guardian or the spy. Thats what i thought, i saw the screenshots today and there are now 5 classes (awesome) and was wondering what are the strengths and weaknesses for each class, eg Infiltrator B=Average, M=Strong, S=Weak, and your thoughts on some of the classes or your favourite class? Any info would be greatly appreciated!