I found that for the past 3 years or so that my UNTRIMMED biscuit works great. Now I do know that vanes loose alot more speed through her than feathers. So if it' s speed you want, shoot feathers. As far as advantage of speed from trimming, from all I' ve read so far your just going to cut your life of your rest in half for a very few fps. Again this is just my 2 cents. I think the rest is the best rest I' ve ever used for hunting.