This show does sometimes revolve around relationships, and there's a lot of kissing. Also, the kids are pretty spoiled and sometimes their world is a little unrealistics.
However, I think it provides many positive messages to balance out the bad ones, such as sexism being wrong. The two main characters, Zoey and Chase, are good role models, being bright and very good problem solvers. The others are a little iffy, though. Some characters to look out for are Quinn, who's very smart but sometimes goes a little far with her "experiments", Logan, who's very shallow and mean, and Nicole, who's flirtatious to the point where it's rediculas. However, the show makes it obvious that all three of these characters' habits aren't normal, so I wouldn't worry about it.
I rated this on for ages 10+, mostly because anyone younger will probably get bored from all the teenage drama.