Since they are NCAA compliant they can hire college coaches and therefore guarantee their attendance. By definition Showcases are not NCAA compliant and can not hire college coaches and therefore can not guarantee their attendance. Top 96 also will put what colleges are coming on their website well ahead of time. So, if you are interested in any of those schools, sign up. If you aren't, then don't. It's pretty simple.
Coaches & Players Directly Interact
Since they are NCAA compliant the college coaches can be on the field and interact directly with the players. College coaches at showcases can only sit in the bleachers.
Hands-On Instruction
The college coach instructors work their butts off. They provide hands-on instruction, written and face-to-face evaluations, and on field coaching during games. At showcases, coaches can only sit and watch.
Day 1 consists of instruction in a station setting, and Day 2 is live game play where every player will play in 1 or 2 games to showcase their talent and learn from the college coaches. Like I said before, it's like attending 15 - 20 college offseason camps in 1 place.
All of this is pretty much straight off their website:
www.top96.com