From Angry Bear: "I have a challenge. Can anyone think of a useful insight in macroeconomic theory which isn't clearly stated in "The General Theory of Employment Interest and Money"?"
The most defensible elements of ABCT are in chapter 16, btw.
One comes to mind - he seems to be much more likely to treat labor like a spot market, which is wrong. And as far as I know he ignores job search.
If you mention anything touching public choice I'm going to be forced to conclude you either (1.) haven't read the General Theory, or (2.) have read it but for some reason will only accept a public choice argument if it's clothed in the language, politics, or citations associated with the modern public choice school.