Congratulations! My DD was pretty excited to get a FF offer this morning too. She was really hoping for prep school, but this sounds like a fantastic opportunity as well.
A FF scholarship is an appointment to lose. Unless the prepster chooses poorly, they will receive an appointment for 2018 and they will be better prepared than they are today. My advice is to take the scholarship.
DS finally got an email this morning telling him to check his portal (which changed several days ago). What's weird is the letter says "you have a new message from the US Air Force Academy Admissions office. This message contains important information about your offer to USAFA Preparatory School." But its actually a Falcon Foundation offer.