Yeah its loads of fun... I wrote a review of mine on hereNice. I'm getting mine in early july. I can't wait.
It would be good practice for when you let him get his hands on the larger caliber AR... everything on it functions just like the larger calibers with the exception of not having a forward assist, which it obviously doesnt need being a .22 caliber ARSweet! been thinking about getting one for my son. He's got a regular .22 with a scope that he plinks around the campsite with when we go deer hunting, and he's been drooling over my AR so this would be perfect.