You should have asked this under “College Selection”.
"My son was accepted to all three schools for mechanical engineering. "
GT is ranked 2nd for ME in the US, and 10th in the world.
“Still waiting on Georgia Techs financial package.”
GT will not give your son a scholarship.
“My son is looking for a well-balanced and fun challenging college experience”
GT is an engineering college and known to be difficult. If your son is looking for a party school, Tech isn’t that.
If your son is in the lower quartile for Tech, he would probably be better off at VPI/Clemson.
Academically, VPI and Clemson are similar schools.
“with a good opportunity for job placement and internships”
GT is the #1 school for engineering recruits ranked by corporate recruiters (WSJ). Tech’s career fairs are multiple days long and additionally have individual career fairs for each major. I’m sure Clemson and VPI have good engineering career fairs too.