The Railgun can be very deadly against a group of ground units as it does penetrative damage which can hit multiple units in a line that exceeds its firing range. It should be noted, outside of its range, damage drops off very quickly. and cannot miss. Unlike every other turret in the game, it charges slowly before firing.
Its main weakness is that it cannot target Air, and Light Vehicles can easily get out of its range before firing, just as long as it is not buffed by a Transformer.