I don't know anything about VMI, but I can tell you that
the two families we know with students at the Citadel are very pleased with the school. One family has 2 sons there (1 senior, 1 knob) and one has 1 son there (knob).
The Citadel has the OASIS program which I've heard is a real benefit to many students.
You can't beat Charleston, SC for a city to live in. It is a really happening place for young people!
We were at the Citadel last weekend. It was my first time on campus. I thought the campus was really nice... but it was not a "New England" style campus such as at the US Coast Guard Academy. The Citadel has a very unique atmosphere as far as architecture goes. Everything there was spiffy. However, the boat yard looked a bit sad which definitely caught our family's attention.
The student body is about 2000, I think. That is a good size. Not too small, but not so large that you are lost. Your professors would certainly know you by name there I would say.
We saw the Cadet Corps on parade. The student body is most definitely mostly white males. We did see several females, and several Blacks and saw both in leadership roles. I imagine the Citadel is working hard on improving the diversity of the Corps. The announcer at the parade listed the values of the Citadel and diversity was one of the values.
The folks at the parade there ranged from regular folks like us... moms, dads, siblings, kids in strollers, some even had their family dog with them... and then there were folks there with coats and ties (men) and fur coats (ladies). I think they were mostly distinguished alumni.
As a resident of South Carolina, I have noticed that there is enormous pride among the alumni of the Citadel. My dad recently had surgery and his anesthesiologist had gone to the Citadel. He was very enthusiastic about the school.