I like it, but there was a park in my hometown called Finn Cassidy, and it was named after a dude that looked like a hobo. So everytime I hear the name Finn, I think of hobo dude.
The only Finn I've ever known was a female. I remember everyone thinking it was an odd name, but she had long blonde hair and it seemed to fit her. I'm not a big fan of it, though. It sounds a bit fishy.