If I remember right '02 UM was an earlier build meaning there were some balancing that the 360 and PC port got but not 100% on this. Other then that '02 UM had 3d backgrounds compared to the arcade, 360 and PC ports. Don't think it effected much.
'98 UM is the same build as the 360 version.but the PC version is the updated version from the arcade.
KOF XI I never heard much different from other then the extra characters not really made for the game issues (balancing not game breaking), and I've had glitchy copies with sound issues. No one really complains about the PS2 copy.