I actually like Pagan although I prefer it for a girl
I don't have a problem with it, but I wouldn't name my child something potentially offensive, even it wasn't offensive to me.
It's not something I'd choose but it's no different than naming your son Christian.
It's a little out there, but I've heard way, way worse. It has a pretty similar sounds to lots of popular names right now (Peyton, Teagan, Logan, etc.), it's got a nice connotation/association for a lot of people, and plenty of people name their kid Christian. Definitely nothing I'd choose, and it sort of seems like they're trying to make a statement, but it's not a horrible name.
I really don't care for it although it has a trendy sound. To be honest I do find it a little strange.
I don't get the appeal of this one at all.