I agree about the age concern. My 8th grader played varsity last year. While it was worth it for the lacrosse, the team is very important. Only half the time they spend together is on the field. The rest is in the locker room and bus etc. The conversations and after practice activities are very different in the varsity locker room than the JV locker room and especially the MS locker room. Most middle school teams are not talking about the parties and the girls the way 18 year olds are. It is, or it should be a major concern as a parent.
I had some serious conversations with my boy before and through out the season. It was something I failed to fully understand when the move was discussed beforehand