I absolutely love the gauss weapons, but honestly, I'm not really sure how much upgrading they need. As it stands, they're already insanely useful, even without autoshot. Dat insane accuracy with the gauss sniper. The only things they don't kill in one or two shots are Mutons, Sectopods, and maybe Cyberdisks and Chrissilids. Basically, if it doesn't have a really high AP resistance, the rifle/heavy/sniper will kill it. While I'd personally love to have an even stronger, autofire gauss to deal with things like Mutons, they'd have to be gamebreakingly powerful to deal with Sectopods.