Beat The GMAT a GMAT & MBA community

I'm trying to get a feel if I'm setting my sights too high or not. I'm hoping my military service will offset my GPA.

GMAT: 700 (44Q, 41V, 6.0AWA)
GPA: 3.03 Mechanical Engineering from Georgia Tech
4 years Active Duty as an officer in the Air Force
Extra-curriculars in college included managing a student run investment portfolio, leadership within my fraternity, ROTC and a service organization.

I'm serving as an Acqusitions Program Manager for the Air Force now. Basically I manage a team of ~25 contractors doing research and development of new technology for the military. So I think my essays will be pretty strong and I come from a unique background of military service blended with business type work.

I'm applying to Wharton, Harvard and Columbia for sure in the first round. I will apply to Tuck as well if I have time to complete the application in the next few weeks. My GPA and GMAT are both on the low side of the scale so what are my realistic chances? As a corrilary, would applying Early Decision to Columbia increase my chances of getting in by showing that I am really serious about making the jump to business school?