Wow, what a nice position to be in. I don't have an inside perspective so I'm not going to be much help. But I am also trying to decide b/w these two schools and have the same academic interests as you - Security Studies with a Middle East focus.
I'm leaning toward Maxwell but my reasons may not apply to you. One of which is its Global Programs. I have not studied abroad and am eager to get this under my belt and I love that Maxwell has plenty of opportunities already set up for students. If you have plenty of abroad experience this won't be much of a plus for you.
I am also attracted to Maxwell's certificate options. While earning my MA I can get a certificate in Middle East Studies and Advanced Security Studies. I also like that Syracuse lets you audit language courses for free. But since you're having everything paid for, that doesn't matter much.
Why do you say Korbel has a good Security Studies reputation? I've heard its students say that but have never seen a legitimate source indicating that Korbel has a top program for security.
Right now, the only pro on my list for Korbel is that Denver is a better location. But if Korbel is really known for its Security program I'll have to add that to my list.
Congratulations on your fellowships! If Georgetown or SAIS throw money at you as well, you're really going to have a tough decision.