Good watch, could watch again, and can recommend.
It feels like this is after all the uproar with Katherine Heigl ("27 Dresses") and she was trying to come back with a smile on her face, but she took the role because it gave her the opportunity to act the awful person she was accused of being.
Gerard Butler ("Bounty Hunter") acts up a storm to keep up with her, with both equally playing off each of wonderfully.
I can't tell the better actor here because Gerard is clearly acting, but he might be acting a character that is acting eccentrically, but I'm still aware regardless of how good it is, versus Katherine who is so natural and seamless that you don't realize she's acting until she over acts per the character following another character's prompts badly.
It doesn't make for the best movie, but it sure is interesting. And I'm sure if you can look past all that, then you can appreciate this veil metaphor of the sexes and a very well written story.
Nothing about this is fantastic, but it's a solidly good romantic comedy.