4 stroke diff
a lot less rpms' alot more TORQUE..(can swing a lil bigger prop) alot more effecient... a lil more maintenance,
the transition will be a lil slower (not much)....but is only nature of the beast ( 2 strokes vs 4 strokes for 1 combustion cycle)
and probable the coolest...is the sound....they purr like kittens...