Those 3 schools are pretty different environments. With Covid, not sure if your DS got to see them all in person, but I'd consider at least taking a day and walking around the campuses, even without a formal tour. App State is only for those who love snow and cold weather because majority of the school year, that's what it will be. App State is also doing a major overhaul on many of their dorms. Lots of new ones opening over the next few years. UNCC actually recently surpassed NC State as the state's largest university, but keep in mind that only about 6000 students live on campus, which leaves it feeling like a smaller school than it is. They have an ROTC living community where both AF and Army ROTC cadets can live together in the dorm near the ROTC building. I haven't researched NC State as much, although I have toured there and had many students attend there. It's campus is must larger, spread out, and integrated throughout a city.
I know that's not really what you asked, but thought I'd share what I've learned from a counselors perspective and research I've done for my own son.