RE: FPS on STS
I do not use the STS on my bow have seen DNK's setup with a couple of others. What will slow down your bow is weight on the limbs or add-ons to the string. Since the STS is mounted to the stock (Riser actually) and does not touch the string until after the arrow leaves the string, it will not effect the speed of the arrow. This is one of the very few things that will help quiet down the bow without reducing speed of the arrow.
Your boddy has a phoenix and is worried about pass throughs? He has more then enough KE for deer with that bow. In fact you will get a pass through with the 150lb model on moose (even with a 2'' mechanical) with a boiler room shot. But remember that heavy bone will stop ev to worry.will not haveen the 225lb model with maxium KE. Shot placement and you