To say the KERS helped him past is true, however, Heikki couldn't do the same with his magic button! So its not the be all and end all.
All season the KERS has been a disadvantage. The extra weight and aero comprimise has written off the chances of teams who wanted to implement it. It is a 2-tier championship but I recall in the 80s didn't we have periods where normally aspirated engines went up against turbos??