Steve, after all the air miles on the 15/6 and its lacklustre results on hovering, I wanted a little more bite. I went too far with the 16/4 at first, not enough engine, but it was available and didn't have to order it. The 15/4 seems good. Slows down nice, but not too much like the 16/4. Lots of get up and go with this one. I'll be putting some time on this one, I like it so far. You never got back to me on how you felt the plane handled without the cowl on. Joe