5 years isn't bad, and 20 isn't that old. It will be a total of 6 years (all full time, no repeat classes) for me to complete my bachelors and a total of 5 years in ROTC. I got two years left but I would much rather do this then OTS as you have to be the top of the top to get in, not to mention getting a pilot slot. Especially as they have been cancelling OTS classes recently. If I were you, I would go for the three years in ROTC, and if you don't get an EA slot after your first year, you can always go OTS but at least you gave ROTC a shot.