The lens is a great lens but it is not specifically designed for macro work. Modern macro lenses are usually symetrical in design which enhances corner to corner resolution in the higher magnification ranges. Schneider does make a 120 Macro Symmar HM and you may be confusing the two.
BTW the buy of the year is the 120 Nikkor Macro that is available new from B&H at a closeout price of $299 which is several hundred dollars less than they sell for used most of the time. If you watn a macro lens in this focal length don't pass this uo, they won't last long.