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.”
(..) Dialogue: Marked=..,Default,NTP,!Effect,But l was wrong. Dialogue: Marked=..,Default,NTP,!Effect,Five points will be taken\Nfrom Gryffindor... Dialogue: Marked=..,Default,NTP,!Effect,...for your serious lack of judgment. Dialogue: Marked=..,Default,NTP,!Effect,As for you two gentlemen... (..)2001 Harry Potter and the Sorcerer's Stone