I've heard these things can really make a difference in your arrow speed. Lets say if they do make a +/- 10 fps difference, and I shoot @ 30", 70lb, 350 grain arrow, would bearrow be 10 fps faster then the advertised IBO?

Now, what string does everyone recommend? I'm going to use this bow for 3-D shooting (about twice a month), and deer hunting (about one month), but I shoot all year round. Thanks.