I'd have to agree with all that was stated above. The only thing I have to add is that being a younger single guy, NB was a better place to live then Irvine. In my opinion, Irvine is all about being clean and proper, where some parts of NB have local hangouts and places to eat/drink - a little more playful life.
Irvine is more of a family environment (heck, the don't even allow liquor stores), which I must say is why I have been here for the past 9 years, my daughter.
Either way, you can't go wrong really...