This is the build you use for lazy group farming like orokin cell farming on dark sector survival or other low level maps.

Typically you will be hiding in a room with three other teammates and all you need to do is occasionally heal yourself (either by running out to collect orbs and loot, having a [Trinity] to heal, using an ancient healer spectre or a Mantis air support Med tower).

In this case, the only two stats that matter are range and efficiency so you can stay hidden in the room as long as possible.

You can add even more range by ditching things like health conversion and equilibrium for stretch/[Augur Reach], but 280% range seems a little excessive to be honest.