How is the Kobalt impact gun working out for you? I've been meaning to try one since I've been impressed with my Kobalt air gun. It looks to be more powerful than the Craftsman C3 gun.
Battery technology has come a long way. We now have cordless guns that are POWERFUL thanks to lithium ion batteries. I have a few cordless impacts that would make most, if not all corded 1/2" guns hide in the toolbox. I use them to remove axle nuts and some crank pulley bolts, and they don't flinch at all.