Yeah the kids are too old, it's alright if you can get someone in their 20's that look 16/17 but a couple of those guys look much older than the age they're playing. Kind of like The OC I guess.
That's why Freaks and Geeks is so great because most of the actors were the same age of the characters, or a couple of years off. I think Martin Starr and Samm Levine were 16 playing 14 year olds but they could easily pass off as 14 and John Daley was actually 14 the same age as his character. I don't mean to keep harping on about Freaks and Geeks but it's definitely worth checking out for a different, original, realistic and funny school life sitcom.