>>27697331i guess. i like them on a longer rifle, because it makes them easier to carry/move with on the march. that comes from having to work with the m16a4, but i can understand the usage with some guys who have heavier ar's.
personally, i only use afg's on pistols/sbr's, as a improved hand stop, but i know plenty of guys who like having a vg on a scoped rifle, as it gives a good grip point for scanning/prolong holds when your using the scope.