Seth Rogen and Zac Efron recreate the first movie almost beat by beat. I didn't find the original copy funny, so you could guess how I felt about the clone!
I am a fan of Seth Rogen. He puts so much of himself in his roles; he's usually the slacker/stoner everyday man who has to deal with some small challenges that happen to be beyond his control. Seth usually surprises you by sneaking in a couple of smart social commentaries here and there. The saving grace of Neighbours 2 is also a few of those comments. This time, Seth and other characters talk about sexism and feminism. References to reverse-sexism, jumping to the other extreme for course correction, and "discrimination not being equivalent to sexism when it is against men" were the highlights of the film.
These comments, however, do not justify the price of admission. The only parts that put a chuckle on my face were a few (less than a handful) instances of slap-stick comedy. So if you are a fan of Seth Rogen - which was the only reason that I watched this movie - you might be better off looking up some of his interviews online with late night talkshow hosts. It would be free, with more funny jokes in a much shorter time period!
Overall, I'd give this movie a 3/10.