I have very mixed feelings on it.
Most porn I've seen where semen ends up on a girl's face makes it feel degrading. There is something about it that bothers me. I haven't been able to figure out what exactly it is about it, but it often feels like there is something in a male star's demeanor that says "Yeah, I came on that girl's face, look how filthy that girl is!"
I've had it on my face a few times, but my partner doesn't seem to prefer it there. I think we like places that are more easy to clean up! When it's his fluid, I don't mind it and don't find it degrading. He's the kindest person I know, so his manner is always "nice"? With us, it would be kind of a silly matter when it happens. I wouldn't mind it on my face a little more often to change things up.