Dip on animation quality.
Overall, I believe the animation through series has been exceptional; however on the very last season which is the legion of doom story, the animation is up to standards compared to the last season.
It's minor nitpick as I observe how fluid and sharp episodes like "the return" episodes based on Cadmus and "epilogue" are the best so far on animation television compared to the following season which was still good but not as candy to the eyes in comparison to the one before.
Am I the only one that noticed this?