A good amount of them get really creepy, some can get really overwhelming, and some just don't know that they crossed a line they really should not have cross, but honestly this is the case with pretty much any fan base, the bad fans are going to make the whole fan base look bad.
In general though, aside from those that make the rest look bad (for various reasons that have probably been mentioned or will inevitable be mentioned), they are pretty fun, and often very enthusiastic, and they very like their ships, which is actually kinda neat to see? Even if it's a ship I wouldn't do it's really neat to see that people like my characters enough to ship them.
It's also neat that I can draw my boy's pretty and they are 100% fine with that. I used to get in so much shit for drawing my guys not man enough (I came from house where the men either acted and looked feminine or androgynous... to me guys having long hair or being short and petite was normal x.x)
I mean, I have stated my dislike for the bad fans I run into a number of times, but the good ones I absolutely love.