For AFROTC only your summer yr as a rising jr yr is when you will go to training that is mandatory to become a POC, and more importantly if you don't go summer field training you will be disenrolled... no commissioning.
Also place in mind when you decide which college you will attend whether it is a host or xtown.
For example. Gtown is host to NROTC, but xtown for AFROTC and AROTC. When you do the visit make sure you do the commute too during the time you will be traveling via the mode of transportation you will be using. On mapquest it may appear to be only 15 miles, but in DC traffic that can be 45 mins, which when you have to be there for PT at 6 a.m. is not fun. DC traffic starts at 5 a.m.
I do know that the NROTC unit there is very good. As a parent of an AFROTC UMDCP grad, I can say the same is true for their det. too....won best large AFROTC det in the nation last yr. I believe the AROTC det has won nationals in the past couple of yrs too.
UMDCP has also an excellent international studies, and if you are in their Scholars/Gemstone/Honors program you are required to do an internship. Our DS minored in international studies, majored in govt. and he interned on the hill his sophomore yr. for Sen. Burr. during the school yr. while he was in AFROTC.