He tried to reason with villains before wanting to just pound them, he was less aggressive, and more diplomatic. "In Blackest Night" shows this very well, same with "Paradise Lost" but then you get episodes like "Twilight" or "Starcrossed" where yeah, he needed to fight, but his dialog and attitude were not Superman-ish to me... not even close. Again this is all my opinion though, so take it with a grain of salt.
Edit: JLU's episodes where he was lame:
"The Return" is an example along with of course "Clash" (Superman was so stupid in that episode... period. I don't care if he was stressed about Lex and all that, Superman acted way out of character just to appease fans or the creators that wanted to see him and Captain Marvel fight.) As for "The Return" Superman and everyone knew how powerful Amazo was... why couldn't Superman say to Amazo: "before you just rush in here and try to kill Lex let's talk about all the destruction you could cause or like you said before leaving Earth you are above all this, why do you need to come back and kill a being far less powerful than you?" (just examples of what he could have said) instead of "Turn back now." Of course the guy is not going to turn back, you haven't given him a real reason to. He knows he will mop the floor with all of them, but had Superman tried to better reason with him it could have turned out better for him (Superman) and the league... (yes, I know the writers wrote what they did, and the story was what it was, but still Superman was lame.) There are many more "instances" where Supes was a flat out jerk. Later I may write more examples from STAS, but for now I gotta run.
Also, again this is all just my opinion on this subject.
D.