Agreed that o3 can be brutally honest. If you ask it for direct feedback, even on personal topics, it will make observations that, if a person made them, would be borderline rude.
But I also find it can get very fixated that some position it has adopted is right, and will then start hallucinating like crazy in defence of that fixation, and then get stuck in a defensive loop of defending its hallucinations with even more hallucinations-by hallucinations I mean stuff like producing lengthy citation lists of invented articles, and then when you point out they don’t exist, claiming stuff like “well when I search PubMed they do”, and when you point out its DOIs are made-up it apologises for the “mistake” and just makes up some more
