Silly question. There is no comparison. The sword of shinee is +e-peen which far outweighs any benefits armor can bring.

More seriously, depends on the rest of your group. People play differently even if you have identical gear. If you're having threat problems, the sword is a very good buy. If you're not having threat problems, then go for armor. However if you have anywhere near competent DPS in equivalent gear to yours, the sword's going to be the better use of 600 myth.