I saw F&D in a special screening at the IFC theater in NYC. It's a thriller and short enough to be interesting to the Kubrick enthusiasts. By no means, it's a must, but for the completionist, I don't think you will regret the 62 min. It has a great scene with a boat going through fog that reminds me Jean Vigo's L'atalante.
Killer's Kiss is a very good movie. The Killing is top-notch noir and one's of Kubrick's best.