javajoystick can't handle force feedback, and if it ever supported force feedback, it would have to use DirectInput. I'm not aware of any other way to do force feedback on Windows.
I've heard rumors about force feedback on the Mac, but I haven't seen anything concrete. The Apple documentation about joysticks (HIDs) on the Mac still says that, 'it's a work in progress.'
It's interesting to see the license differences. I'll have to meditate about changing the license :-/
It's interesting to see the joystick speed differences. There isn't much of a difference, but there is a small difference. I know that JDKs sometimes take a while to warm up for performance testing, but you do make a good point. I'm presuming that a normal joystick was used. The polling works differently when it detects that more than the generic 3 axes are used, which causes it to get significantly slower. It could also be due to how the function is declared (static verses "virtual"). Oh well.
I'm personally happier about the javajoystick model though. I like the ability to have more than one joystick in use, the ability to add Java style listeners to a joystick, and the ability to pick and choose which joystick is used.