It is my very honest opinion that you must use a MOUSE, not a joystick for games like UT. There just is no comparison between the results. If you need proof, seek out the better players and ask what they use. You are actually the first person that I've heard even mentioning using a mouse since Duke3d came out many years ago.
When I first started with Wolfenstein and Doom (the original 1.2), I used a joystick. Though I was good with it. However, then Duke3d and Kali came about and I was subjected to many players (using the mouse) and they were literally running circles around me.
If you plan to play against humans and want to have a decent chance at winning, use the mouse!