Originally posted by Bialaska
JLA and X-men cater to different people with different tastes.JLA is more focused on protecting Earth against whatever menace comes up this time. They are heroes, everybody knows it and their enemies are of a suitable strength to challenge them.
X-men are focused on mutants and what sets mutants apart from humans. They are attempting to be a bridge of diplomacy between humans and mutants, while preventing too many mutants ruining relations. Their challenges are suitable to challenge them.
However if you take an enemy from JLA and put against X-men, you'd prolly see the X-men get wiped out, while JLA would have no challenge in smacking up an X-villain. That's also why comparisons are never really the best thing in the world, because they operate on different scales.