I disagree a bit with Old Navy. IMHO, the SA is also important b/c it's where you'll spend 4 years of your life. And if you hate it, you may quit and never get to see the differences in the services themselves. If you end up staying for only 5 yrs on AD (obviously a pilot owes more), nearly half of your total commitment was at the SA.
USNA is in Annapolis -- a decent town that is right outside the Yard. You're close to B'more and DC. The Springs is also a great place, but the Academy is a bit outside of the main town. It's not super close to much else, other than terrific skiing! As to how the two schools compare in terms of life as a mid/cadet . . . don't have sufficient knowledge of USAFA to opine but I suspect that the SAs too have different cultures.
The Navy is a seagoing service. During your time at USNA, you'll spend a decent amount of time learning about sea-related stuff (e.g., damage control, navigation) and being at sea (mostly during the summer). If you chose to fly (and are selected), chances are good you'll be assigned to a carrier-based squadron. So, if you don't like the water, you might not enjoy your time at USNA and, upon graduation, will have to hope you get Marine ground or one of the relatively few aircraft that is land-based (e.g., P-8, C-130).
USAFA cadets obviously spend their time more focused on flight/aviation types of things and, if memory serves, there are numerous opportunities to fly as a cadet -- something that's pretty limited at USNA.
Agree that DS must consider what happens if he can't be a pilot or even an NFO. It's not so much eyes today as other stuff. Knee gets blown out, for example. Also, what if you aren't selected for pilot? USNA has a broader range of warfare specialties upon graduation but the opportunities to do "staff" type jobs (intel, supply, aviation maintenance) are essentially nonexistent unless you're NPQ. In the USAF, there are pilots and everyone else. That said, there is a much greater likelihood of doing what I call "staff" jobs (missiles, intel, etc.) even if you are physically qualified. That is NOT to denigrate those jobs -- rather to indicate they are more static in that you're not on a ship, aircraft, sub, leading men/women in ground forces, etc.
In any event, DS can't go wrong . . . unless he picks USAFA. Just kidding.
Though the USN definitely has better looking uniforms.