I actually find the turbocharged GGs somewhat underwhelming against the AI. The overkill doesn't decrease the amount of damage you sustain by all that much, or make conquest all that much faster.
It's the Paper Makers that are insane. Big money -> Happiness buildings -> longer sustained early push -> more cities -> more early Gold and Science -> more Happiness buildings...
Ignoring Happiness is suboptimal because it doesn't permit you to take advantage of the massive growth potential from Maritime allies, and nerfs your Hammers. Also, Science and Gold buildings are stronger in fewer, larger cities.