Very few Older pokemon add a 10 To one of their stats! Game Changer maybe? List is here http://www.serebii.net/xy/updatedstats.shtml
Most noticeable (might defenitly help imo) are ...
Raichu ⇒60 90 55 90 80 110(used to be 100) Now its not tied with several 100 speed pokemon good right!?