The "is vlad mad?" question is - IMO - more a case of "how mad is vlad" - I would definitely say he has a degree of paranoia, obsession, a detachment from reality and megalomania - all his recent actions suggest that. But to what extent?
I dont buy the "no - its his cold, ruthless logic at work" . So an increasingly desperate and isolated Putin openly threatening to use nukes definitely does put the shits up me - because I cant say with 100% certainty that he isn't batshit enough to do it.
And yeah - im finding it scarier than the cold war because you believed that both sides were rational actors doing game theory stuff - so post cuban missile crises we never got close to an escalating political crises that could have led to WW3/nuclear Armageddon. We didnt really know about the far too close comfort near accidents.