I used them for a little bit just to test them out. What I found is that they are really not that durable. It seemed as though after about 10-12 shots with the same arrow, the fletching would get wavy - definitely not a good sign. I also had my regularly fletched arrow (stock carbon express vanes) and an SVL fletched arrow in a bit of an unscientific contest. I had my wife sit about 10 feet out of the way and halfway between me and the target just to see if she could hear any difference in the noise of the arrow as it passed. She indicated that there was no major difference. Since there was no major difference that could be heard and they weren't holding up as I thought they should, I have stopped using them and started using the NAP QuikSpins. I've heard mixed reviews on these also, but I have only been shooting them at 20-25 yards and they have been working extremely well for me.