Game seems much more difficult on immortal now with the patch. AI has always been very good at Science at that difficulty but with the bug fixes and apparent valuation of luxuries for science civs (where they willingly trade culture items away) a science runaway has to be stopped early.
No more 50 turns catching up to an AI sitting at 68 techs but not launching mars project.
No more 50 turns catching up to an AI sitting at 68 techs but not launching mars project.