If I'm looking at on-time stats to see if they should have a bearing on which airline I fly, I care a whole lot about the definition of "on-time." I don't care about being 15-30 minutes late, but I do care about not being 2 hours late.<p>Again, this sort of thing should be adjusted for routes and airports, but depending on your purpose in flying a route (going home, where your parents will pick you up? flying to LAX to catch an intercontinental flight with a tight connection?), a more granular breakdown is important.