For me at least, I don't think doing engineering is much harder than other majors especially since the AF will let you pull it out to 5 years since it's a tech major.  However, most importantly do what you like.  In my case I know that I'd much rather be sitting doing EE homework than writing a poli sci or history paper.  Don't get me wrong, engineering is a lot of work but I know I'd rather be doing it than some fuzzy major and my gpa is better off because of it.