It strikes me that a lot of the adjustment issue is related to geography. Out-of-town BTs, geirim, returnees (born FFB, went off and came back) etc. are pretty much accepted on their own merits. That could simply be that in smaller communities people can become known as individuals, rather than labels.
In places like NYC, though, where everybody seems to belong to an “identity group” anybody who is different is going to have problems. If you wear the wrong color shirt, you’re beyond the pale. If you go to the wrong sem you’ll never get a shidduch. Once upon a time people becoming frum out-of-town wanted to move to NYC because a) that was where the “real” Yiddishkeit was based and b) that’s where everybody went for a shidduch. Now, people are moving to Boston, Baltimore or Chicago, simply because it’s now known that NYC doesn’t welcome “outsiders” any more, and everybody is too busy calling everybody else unpleasant names.
The moral here? When you’ve got real achdus you don’t worry what music the next person is playing on their CD, and you aren’t afraid that a BT child will influence your children instead of the other way round. When major groups of FFBs start accepting each other, eventually they may get around to accepting BTs too.