Good stuff. They help my FOC as stated above and my KE is so high I have nothing to worry about. My KE is 72. If I lose a little here, I'm still doing just fine. Thanks for the link!
One thing that stands out to me is they may be questionable for "whitetail" setups. I know most whitetail hunters don't pull alot of weight, have different setups, usually only use 100 gr broadheads and don't shoot long distances. This seems to be the general trend that I see in here. I'm an Elk and Mulie hunter that will shoot to 50 yards in a blink of an eye. They work with my setup, so I'm a fan on them and will pay for them. They are still cheap to me when you consider the overall cash spent on bow hunting in general.
Hopefully you can see why I like them? They have benefits for me and they give my setup some improved performance -- thus, I'm a believer in them.