OP: if I were you, I would wait until fall. Just from what you've told us, I feel like, should you rush spring and get/take a bid, you may always look at the other two and say "what if", which is one of the worst feelings in the world (and totally unfair to the sorority you'd be in)!! Rush fall
open minded and see where it takes you so you know you exhausted all your options.
I know some girls at my school who dropped pref last year, re-rushed this year, and are utterly in love with the sorority they are in. Some even got their top choice from last year (that's not to get your hopes up, because it's a very rare occasion!). The moral is, I don't think you should limit yourself if you're still not sure of what you want.
If you should rush and get a sorority you're unsure of still, STICK WITH IT, because they could always win you over the more you get to know them and it's not like you're bound to them forever (before initiation that is hehe).
On another note, I think one of the big reasons you may have come off as snobby is because you asked if you should "settle" for the other 2. That word has a pretty negative connotation and you really shouldn't think of it as settling, because I'm sure those chapters have some amazing girls in it. Not preaching, just saying!
Good luck!!