This build is designed as a utility build for melee builds that require life steal.
This build is not really designed to see much usage but can be useful if ranged combat is required. However the main purpose of this build is to save a slot on the melee weapon by removing the need for [Life Strike].
This allows the player to add an extra mod in the melee build to increase damage, range or attack spead.
When I have this equipped I never use it unless I actually have to shoot something from a distance and my melee would not be able to do it.