Began using them this year, went thru two dozen. You will break a ton of them target shooting for sure. In my personal comparison tests they perform as well as blazers out to 30 yards, longer ranges the increased drag makes them hit a bit lower. Shot the only deer I got this year with them also but in the process found another major drawback- when dragging the deer out thru heavy brush they all got pulled off the arrows in my quiver. Next year I'm gonna just use blazers, they DO work and fly very well but the minor drawbacks are enough for me to not use them.
BTW to answer the above post, yes they are noisy in the air but people claim the deer cant hear it because the noise is behind the arrow and no regular push in nocks work fine as long as you arent using fancy target nocks.