Whats the difference between the Nike Sumo 3wood and the Nike Sumo2 3wood.. (The square one)?

Am looking to purchase a 3 wood and have narrowed it down to the Nike Sumo or the Nike Sumo2 (Square head).. (Please don't recommend hybrids or other brands..i am sold!!) Has anyone used both these clubs? Is there a major difference? I am about a 15 Handicapper with decent length (7-iron 160y , Driver-260y).. Any suggestions pleaseee!! Cant seem to deceide between these two !!