Difference is there certainly... not as big as it was from 2013 to 2014 but still some really high yield topics n images added and also many corrections made... if u r early in ur preps.. i wud advise using 2015 but if u r already in the last 2 months... just peep thru it once and add whatever u find extra into ur 2014.. dont need to shift totally to it so late in ur prep...