I too want to love retro Gatling but I stopped using it after seeing that it's just not as good as the regular one.
I don't use it all that often in multiplayer as I don't like being a sitting duck, even with the armor upgrade in GW2, but it can certainly be effective, and Gatling campers are one reason why Time Park is such a bad map for multiplayer most of the time. Taking them out with a ZPG is so satisfying though.
In BfN, that reload Gatling ability can take down a boss singlehandedly if you don't get knocked out of the mode; just aim for the head and crit away and keep getting ammo to crit more for more ammo, it's pretty sick.
