I used him in the first adventure I ran to give the party access to a ship. One character was being played as an in-your-face jerk (the player wasn't far behind, he kept whining "If this was D&D...")
Captain Jameson popped the character in the head with a revolver when the character was dinking around with the engines while bored during jump "to see what would happen."
Later, I used Jameson again as a possible route to get out of a hell-hole planet. They put together a plan to get Jameson what he needed and meet him at the edge of the downport, then haul the goods to the ship when Jameson gave them the green light. The other players told a new player about the previous adventure. The player couldn't resist. While they were loading the local contraband the player had his character start screwing around.
After several minutes of antics on the loading ramp slowing down the loading, the character saw official vehicles driving around the area. He started waving and yelling to them. Jameson put a knife to his back and got him to shut up. Once the ship was loaded, the character started arguing with Jameson. He started grabbing cases then throwing them around. Jameson pulled a revolver, put two rounds in the idiot, then shoved him off the ramp as it closed.
After that, Captain Jameson became a running gag. Picking up on the new Watership Down film, players started saying, "You'd better behave, or the Captain will get you."
He ended up plugging one more character, and accidentally on purpose spacing another in later adventures. In both cases they were being destructive and imbecilic.
I stopped using him when I started a new campaign in college. I haven't thought of him in years. Maybe it's time to bring him back. :devil: