I originally purchased the 15-22 for my 11 yr old son but the whole family is now involved with it. It is a blast for the WHOLE family. It is our first introduction to the AR platform and has been well worth the enjoyment.
I to ruled out the more expensive options of uppers and lowers or just going with a straight 5.56 but decided on the 15-22 to begin with due to costs. I am glad I went this route as I never imagined how much fun it brings and the daughters and wife do not hesitate to go shooting now.
You can't go wrong with the 15-22.