Bat Man in Detective comics, and Gotham Knghts is way better than Batman in JLA for two good reasons.
Gadets and brains.
JLA Bat man builds lots of mechanical stuff, and while he's more clever than the others he's not as sneaky and GK Batman.
For Batman to work well as a charcter he needs three basic aspects.
Slight hold on reality. His best villians have either have minimal semi- non exsistent powers or no powers at all.
A hint of insanity. His best villians are crazy, but a guy that dresses up as a Bat and beats up criminals isn't exactly your poster boy for self actualization.
Dark/gritty character flaws. Bruce Wayne the billionare soclite that everbody thinks is a fruit hides the fact he is a vindictive, OCD, Vililantte who supressed his anger to the point of a schitzophernic breakdown and creation of a shadow self.... He is not the full deputized agent of the law. Jim Gordon the police comissioner wrestling with his sense of the law and duty vs a nutcase that gets results. Selina Kyle a copy cat villian more in love with getting the attetion and affection of Bat man than pusuing a real crime career. The Joker, a physically weak, but intimidating figure based on his personal abanodon to health and survival. The Pengin, born looking like a bird, shunned by society reall mad about it. Riddler, so eager to prove he is smarter than bat's he leaves clues that get him caught. Two Face... well you get the idea.
Now compare that with JLA: A bunch of over powerful ego maniac's that walk around the station like it's their personal olympus.
Who do they fight... Who can they fight?