Big deal! Who cares who Max Martin has worked with? It's just like something i read the other day...people were slamming Tommy Lee for talking with one of the Backstreet Boys on how to get a heavier sound for their next record. The day artist start limiting themselves musically is the day it will all start going downhill, in my opinion anyway. It's all about growth and gaining new knowledge to give you the edge you need for whatever your doing.