I think it depends on your setup as to whether it's worth it or not. I think that fall-aways are a great innovation, but really shine IF...
You use a release on a fast setup with fixed blade broadheads(the larger the cutting diameter the more important it becomes) and large(4-5"
A big fixed blade head on a screaming fast bow will have the tendancy to sheer or plane. Many times only a larger fletch and/or a helical will diffuse this; Vain clearance becomes a problem with any other type of rest.
They'r great for other applications too as I believe they ease the tuning process. I wouldn't reccomend them for a finger shooter though. Just my thoughts.