I've got some and have tried them. I fletched the first half dozen with a helical fletch and here are my observations. They do rotate a lot more than standard fletching. They do slow the arrow down, which is noticible. But they shoot just about any broadhead to the point of aim. I haven't noticed any increase in noise. I test this buy shooting by a video camera then listen during the play back. All arrows make noise. If you think any arrow is loud with field points, try it with a broadhead!

Anyway, I'm going to try a half dozen with a slight offset and see how they do.

Standard disclaimer: The proceeding is just my observation, no scientific equipment was used in the testing of these fletching. Just a good dose of common sense.