I currently have 2 arrows fletched with these vanes. I haven't got to shoot these very much yet, but with the few times that I have shot them, I am very impressed.
I don't shoot off the shelf, so take my results as you please.
But, from the shooting that I have done, I can honestly say that the vanes shoot as good, if not a little better than my feather shafts. It may just be me, but even with a bad release that puts my feathered arrows to the side of my mark, these vanes still guide my arrows right on. My groups at 20 yards are pretty good and these vanes are right amoung the rest of the arrows, so no new tuning is required.
Because, these seem to shoot so good, I have thought about fletching all of my arrows this way, but I still like my feathers, so maybe only half. I will try to provide a full post on these after I have been able to shoot them more and get a full feel for there flight.