The service u need to return adds up to the length of your degree + 1 year.
I applied as a pilot to get the ADFA education award, and was told my service would be close to 21 years, even tho my training was about 5....
Its coz it so god damn expensive....
Mind u, the education award was fantastic, the laptop is great and will help me soooo much at uni...
The other pro's are tax free income, assured job, great health benefits, income while u study (but u still pay boarding costs), gradual pay increases throughout your career, continual opportunities to attain promotion, and a fitness level that will assure your good health, and the opportunit to travel
Cons are the lack of opportunities for extending your degree past honours (unless u like top ur class), regimentary uniform while studying, the physical workouts, potential to fight in conflict, unpredictability of job placement (thought they are a bit better if u hve a wife/family, but girlfriends are less of an influence), the constant movement between bases in training.
Hope that helps

matt