the monster green/black reactive has the first generation monster core and has the powrkoil 17 reactive coverstock. the monster screamR has the lightbulb shaped core first found in the rhino pro line and the n'control reactive coverstock. the monster screamR will handle the drier lane condition better. both may work on a medium condition depending upon your style. i loved my screamR---great roll and a low price. good luck.