This was a pretty fun movie to watch. I like this particular type of story, so I knew going in that I'd have some fun with it.
Zac Efron is actually a decent actor, and he was far less orange in this movie than he typically is.
He had great chemistry with his costars, played the displaced middle aged guy pretty well, handled the fatherly vibe with his son and daughter in a believeable fashion.
My problems with the movie include:
1) Matthew Perry and Zac Efron look nothing alike. I'm 26 years out of high school and while I don't look 17, I still look like my younger self.
Maybe David Cassidy should have been chosen for the older role, but then they would have had to go for a much older 'older role' which would have made the wife/kid attraction seriously creepy.
2) The mom hardly EVER interacted with her kids. She had some interaction/fondness for her son, but almost none with her daughter. When the daughter and mother were together in scenes it was if they didn't know each other. The daughter is dating a very inappropriate guy who behaves abusively to the son in their own house and neither parent was aware?
Overall, fun movie to watch. Could have been far better if the writers had bothered to script a better plot. Lack of back story on the characters made it hard to really understand the wife's rage, or the children's complete dismissal of the father.