We started out the same as Lorel, but I think we're ending on a different note. GS10 is becoming more social with his age group, he can now find things in common with other 10 year olds. Most, or many, 10 year olds like Pokemon, Harry Potter, baseball cards, video games, movies, etc. GS is younger than the others in his den, but still within the range for that grade.
There's always the opportunity to go deeper with the projects the kids do. For example, study aerodynamics, friction, & wood finishing techniques while building a car for the pine car derby.
The major reason not to skip, is there's no place to go after WEBELOS II except Boy Scouts. There is a minimum age of 10 before they can cross over.
