I finally remembered something that bugs me - when people say that "playing fretless is easy"! I always wonder if they can really play well or if they sound like the guy playing the wishbass earlier in this thread!
I must say, I was inspired by the video of the Police live at Hatfield from early in their career - as others have mentioned, his intonation is off sometimes, especially when he's singing, but for some reason it doesn't matter! Maybe there's more leeway because it's a three-piece?