I've actually never met a sister from another chapter that I didn't like and who wasn't a total sweetheart to me. Now...the girls in my own chapter.....that's a different story!
Also-I've only ever met a few girls from different sororities that I didn't like. Most of the girls I've met that are in different groups have been sweeties too.
I think you are less likely to meet a rude or mean person from a different school or chapter b/c we all know to be nice to people we meet! We are more likely to dislike someone from our own campus or a near by school b/c we are together all the time and of course there is going to be some sort of conflict or whatever. I mean, no ones' perfect!