I agreed to let him join us, even though it was 'against my better judgment'. [=even though I did not think it was the best thing to do]
In my 'judgment' [='opinion'], the stock has performed badly. = It is my 'judgment' that the stock has performed badly.
“Were his policies good or bad?” “I'll have to 'reserve/suspend judgment on' that. It's too soon to know.”
(..) Wolves? What do we do? I've got this. You just... don't fall off and don't get eaten. But I wanna help...No. Why not? Because I don't trust your judgment. Excuse me?! Who marries a man she just met? It's true love! Christopher! It's Kristoff! (..)2013 Frozen