Are there any differences between Supergirl's leaked pilot episode and the broadcast one or are they exactly the same? I read a few articles about complaints with the leaked episode and I also didn't like a few things. So did they change anything (maybe even as a reaction to the complaints) or just keep it the same?
If you're asking about significant changes to the plots, characters, etc, then no. The episode that aired on 10/26/2015 was the same episode that originally leaked in the spring of 2015 in every meaningful way.
It seems like there were some very minor changes made in the editing process, probably for time constraints (e.g. I there's a line of dialogue, when Kara returns to work after her first public superhero activity, where a coworker calls her a "life saver" that I didn't hear in the final episode), but nothing that had any impact on the content of the episode.