I assume that your son will be applying to both AFROTC and AROTC. Remember, if he receives one of the scholarships early on, make sure he accepts the scholarship while he waits to see if he is awarded the other, then he can make his decision and at that time decline the scholarship he decides not to use.
One of the biggest differences between AFROTC and AROTC is in how the program works.
In AROTC once he signs his contract he just needs to meet the requirements of his contract and he will keep the scholarship and commission. Every cadet in good standing will go to LDAC, there is no board or selection process.
In AFROTC he will have to go before another board to be selected to go to SFT the summer after his sophomore year, if he is not selected he will most likely lose the scholarship and be dropped from the program, there are options but I'll let others explain those.
Thompson brought up a great point.
If your son completes AFROTC and commissions he will be guaranteed Active Duty with no option to go reserves.
AROTC does not guarantee Active Duty, it will depend on where your son is on the National OML after LDAC. It will also depend on how many officers they need in Active Duty that year. If your son falls below the number needed for Active Duty he will be forced Reserve/NG. In AROTC the cadet also has the option to choose the Reserves or National Guard if they want, AFROTC does not have this option.
Just a couple more things to consider.
Terrific information! Thank you very much.