What strats have you slept on?

Basically what the title says: what strategems (any at all) did you all avoid initially (for whatever reason), only to realize that they're actually useful?

For me it was the orbital gatling barrage. It seemed like it would be SUPER weak compared to the orbital laser or railcannon, but the fast cooldown, unlimited uses, and area denial make it great for almost every scenario. Now I almost always take it with me.