If AAA and BBB were both stable chapters, I don't think that it would matter so much. If you have friends in them, and they're able to recruit women (even if BBB is the "geeky/weird" chapter), you want to go where you'd have the best experience.
If I felt that BBB wasn't stable, and that they weren't as able to recruit women, I wouldn't put BBB as my first choice. Having casually worked with a now-closed chapter, there were lots of women who ended up cancelling their memberships because the strain of perpetual recruitment became a mental, physical, emotional, and social drain.
If you drop out of BBB, it won't matter how strong they are nationally, because you won't be one anymore!
Another thing that nobody really touched on is alumnae orgs. If you love your org, it's easier to keep up with it if there is a strong alumnae org near where you choose to live and work. BBB might be great nationally, and even fun for you during your four years, but others might pick AAA because it's fun on-campus and fun *regionally* (say in the northeast or midwest), even if it isn't seen in more than 10% of campuses in the west or south.
Of course, half the time you don't really pay attention to where your alumnae orgs are, because three years from today is just, like, forever far from now, y'know?
I had fun with my local while we were on campus, but they had little alumnae support while on campus, and less off campus. I don't keep in touch with most of them. But I love the fact that ADPi has three alumnae chapters in the Chicagoland area! Lots of opportunities that I never thought I'd have in college...