They're my favorite parts of Voyager. I've been a big Robert Picardo fan since I was a kid, I grew up on Joe Dante movies and he was in quite a few. He was awesome/hilarious in Innerspace. I've always liked the idea that Paris MIGHT be Locarno from TNG: The First Duty. I know technically he isn't and McNeill himself says they're different characters, I think they just didn't want to get sued.
The story is that they wanted to use Locarno, but the lawyers told them they'd have to pay the writer of The First Duty royalties for the whole run of Voyager. So they decided having Locarno wasn't important enough to spend the money, and just changed the character's name.