A RDS will do just fine for SHTF, or 200 and in. There's no need for overkill for a defensive rifle. Unless I NEED magnification, I prefer a RDS, as it's faster and lighter anyway. There are guys at classes that easily ring steel at 300+ with nothing more than a RDS. For precision.... well that's a different story. But for SHTF, I'm a fan of "keep it simple, keep it light".