I never use the stuff in tubs. I don't know the technical stuff behind it all, but the tub stuff seems to be whipped, much softer, etc, and just doesn't do well at all in baking, IMHO. Your mileage may vary. I also don't use the walmart brand of margarine, unless everyone around here is out of Blue Bonnet. I will swear by BB for baking, though.
I would love to know the scientific difference on the tub vs. stick margarines, though, if anyone knows what that is...

I'm a geek like that...