RE: 85 or 100 grains?
To be honest, 15 grains just really don't make a hill of beans worth of difference....You'll gain MAYBE 3 fps, and yeah, the arrow will act stiffer, but w/ only 15 grains of weight difference, unless you are RIGHT on the line, it won't matter. If you are currently using 85's, don't switch, but if you aren't shooting anything yet, go w/ the 100 grain.