My rebbeim told us not to use them. So we don’t. Otherwise, I dunno much about them.
I do particularly enjoy the way MO rabbis get themselves all in a tizzy about it. I actually once saw an article by a rabbi who takes himself seriously, suggesting that people should refuse to attend a wedding where they aren’t using a prenup.
Imagine that. For all he accuses us of imposing chumros on others, this guy wants to impose that nobody can go to a wedding where they don’t do it the way HE thinks it should be done. Nice.