Oh god, the pun, it hurts!
I haven't found Dyson Gatlings to be very useful. Maybe it's because I always do 120 planets, but they just don't seem to reach past about two hops around the Sphere. Their spawn rate is too low to overcome the AI's defences. Of course, it's probably far more useful if the Sphere sits just one hop away from a high-value planet, but so far every time I found it it was surrounded by wasteland, and usually it sat somewhere in corners or dead ends where not even the location itself has strategic significance.
But that's just my bad luck, so what.
However, Golems.
(Hard) actually is the new easy. The Strike Forces that threaten you are pitifully weak against mobile defences, and the Golems you can find are so ridiculously strong that you can really afford to have half your fleet on strike force interception duty. And once you have several golems, using them with a small fleet screen to minimize damage to them (and repair costs) means you can take on just about anything - winning the game is just a matter of going through the motions.
So be wary of the Broken Golem minor faction. As long as your game is somewhere in between medium- and long-length (as opposed to short, low-planet, high AIP/min), you can really take the challenge out of things by picking up those beasts.
And never, never, never ever research Scout Starships mkIV or build Scout Drones mkIV. Destroys all suspense, really.