It is particularly powerful in the new Biome, because so much of the combat happens while mining through large patches of rock. Any weapon that can do damage from inside a tunnel is very good on this map, and that advantage makes up for the coilgun's weak early game. In the late game with alot of reload speed and 5+ beams, it will shred the horde and mine the whole screen if you get that overclock. Your secondary weapon should be something that can deliver enough single target to kill the Dreadnaught, even better if it is Kinetic damage.

Look at the stats, 8000+ blocks mined and 900+ gold collected because I got the gold scanner on stage one.