diffs between top tier women and lower tier women

There is no such thing as a top, middle or a low tier women. The way chapters achieve their places in tiers is basically based on attractiveness rated on by guys, and not much else. Each chapter has strengths and weaknesses but all chapters are meant for building a sisterhood, so you should keep that in mind. Yes, while some of the top tier houses, as you may have heard, have members that may be considered superficial but that judgement could be from one persons bad experience with one member and shouldn't be used to judge a chapter overall. Personally, I know many women who are considered in "top tier" sororities that are very down to earth!