The Stinger is a great bow. I have a 2009 Stinger I bought this spring and love it. Its fast, quiet and quiet. It sounds too me youre using too heavy of an arrow. Im not sure why you feel the bow isnt fast enough. Its plenty fast and Im not sure why you feel the need to have the 70# limbs maxed out. Try a little lighter arrow and maybe a lighter broadhead but i would stick with a 100gr head if you can.