I commissioned as an Air Force ROTC 2Lt in the Spring of 2013 and utilized the USAA Career Start Loan.
I was offered the standard $25K at 2.99% to be paid off in 5 years but with a payment deferment of 6 months after my commissioning date. Monthly payments came out to about $471 a month. However, as a single Lt, I wanted to try and get it paid off as soon as possible so I rounded up to $250 per each bi-weekly check to equal $500/m.
I used the majority of it to pay off my higher interest loans at 6% or above. I saved a couple thousand to help with some end of year expenses and getting set up in my new location before my PCS reimbursement funds kicked in.
I never calculated how much I saved by doing so, but I'm happy to report that I was able to get student loan free by 2017.
I commissioned in May so I didn't have to pay USAA anything until November of that year.
I was a lucky one and got orders right away and reported to my first duty station in July. So I started getting paid by August.
I had a couple peers that didn't get orders until 6 or 10 moths after commissioning (all about timing and needs of the Air Force).
Remember you have 12 months within your commissioning date to apply for it. So if you think you may be delayed to get orders and don't have a part time job lined up to fill the gap, you may want to wait a little after commissioning to ensure you'll have a job by the time the 6 month deferment is up.