Daphne got a pretty much universal fanon personality. I don't think I'd enjoy a warm and fuzzy Daphne. Astoria is even more of a blank slate, which is both good and bad.

 

Let's say that Astoria is a closet Boy-Who-Lived fangirl (as she'd need to be in Slytherin) and Harry finds out and proceeds to nail her behind the greenhouses--because he CAN (JKR essentially gave us a neutered Harry, so this would be a huge improvement).

Then we he later sees her kissing Draco, he can ask him cryptic shit like "Hey Malfoy, how's my dick taste?" and point and laugh with his boys.

 

lolol I think next time I get high I'm going to write that one-shot.