I think that on average, Geoff Johns is a decent enough writer, but his retcon that Maxwell Lord was a villain might possibly have been the worst thing to come out of Infinite Crisis. Lord was always portrayed as morally grey character, but it was abundantly clear that he cared about his teammates. At his heart, Maxwell Lord was a good person. Hell, the entire Breakdowns crossover between Justice League America and Justice League Europe was built around the fact that readers wanted Maxwell Lord to recover from his coma.
I think that redeeming Lord by retconning his actions in Countdown to Infinite Crisis as a form of mind control would be easy enough. However, do you think it's too late to redeem Maxwell Lord?