I have actually been redt to a couple of YU boys. My father’s family is affiliated with YU, and most of my cousins go there, so the suggestions have come from my aunts. My father told me not to reject them out of hand, since they could be very good boys.
I personally think that yeshivish hashkafos and YU ones are incompatible. A number of my cousins are really solid YU boys, but their whole mentality is different. The entire approach to halacha and hashkafa (especially when it comes to tznius between the genders and Israel) is completely different.
So while I would not say no out of hand if I got a yes from a YU boy, I would be very wary. That is my personal opinion, though, and others are entitled to disagree.