I work at a super major, and in my experience job grade >> all. You can kick butt at your job grade, but your accomplishments and how people look at you are filtered by job grade. If you are an A, they will look at you as an A and would consider a B for that B job 5 times before you - you're just an A. On the flip side, if you climb the career tree too high and don't continue to excel, you put yourself at risk.
Take the job that is more likely to make you a director or VP down the road. I assume you're already on an upward trajectory within the Planner group, hedge your bets with an MBA or some of those procurement certifications, APICS or NAPM or something.
