A large part of this romantic comedy is quite enjoyable, and helped much by the delightful and rather fresh performance by the lead, Russell Brand. He also gave me one of 2011's best performances (Get Him to the Greek), so it was great watching him offering similar acting style.
The rest happens to be the formula that too many Hollywood romantic comedies tend to adopt, and it's so fucking annoying. Nick Nolte's character was neither interesting nor portrayed well. In fact, he's embarassing. The lead girl is fucking desirable, but her character was made annoyingly uptight, since it had to fit in with that formula I mentioned.