the quick spins are heaver 28grains more than 4'' feathers.10 grains more than plactic fletch they also spin the arrow faster in combination use loose arrow speed confirmed it threw the cronie.they are also a pain to fletch with the air foil tab on the back of fletch.i was at the biggest pro shop in my area yesterday they all tryed the new vane and went back to the blazer vanes.they don't hit in the same spot as reguler fletched arrows. they hit to the right about 2'' with field points.