I adore this name. It's cute enough for when they're young, but dignified enough to carry them through adulthood. I'd use it if my surname wasn't Phelan, which is an Anglicised form of this name!
It makes me think of a brave elf-prince warrior in a fantasy story (actually, that's the kind of character I'm using this name for in one of my stories). It sounds dark-green to me (if you can understand what hearing names in colors means).
I love this name! It's quite uncommon, and it's Irish (I am fond of Irish names, for some reason). If I ever have a son, I am going to name him Faolan (of course, by the time he's in middle school, he'll probably want to kill me, because others might shorten it to 'Fay', which is a girls' name.)