Post-op... If they were hot (and I were single), I'd probably think twice, ask how much they paid for the surgeon (need a high quality job here), I'd fuck somebody who's had the surgery into a woman.
Date... probably not. Not for any personal reasons, I'm just a bit of a dick and care deeply about what others think of me, the thought that friends and family wouldn't approve is something that I wouldn't like. Can't come out with any hollywood bullshit about love, because if I don't date, I ain't falling in love, so that situation will never come to play.
As for those saying no because they can't have kids........ daaaamn, that's like the biggest positive I can think of. One of the biggest risks of casual encounter sex has been eliminated. As for others risks, I'm also betting you're safe from quite a few STIs that way.