The PC Versions of the Star Wars games run fine, but the console version of Jedi Knight were terrible, framerate was all over. They have no exucse though, the Xbox can run Halo at a steady framerate and yet Lucasarts can't get Jedi Knight, running off the age-old Quake 3 engine with no fancy bump mapping or anything, to run properly?
That said, Battlefront, in single player at least, ran silky smooth on the Xbox no matter how much was going on.