Terrell Owens had a great work ethic as well.
I'm not saying Brown is anywhere near the jerk Owens was, as he seems to care more about winning and the team than Owens, but Brown is still a stats guy first and foremost.
Roethlisberger has called him out in the past for bitching, as if he hadn't already had a zillion balls thrown his way prior to that, and I've too often seen Brown visibily pout/show frustration when a teammate catches a TD in the redzone instead of him.
It was also widely speculated in the local media that they went out of their way to extend his 5/50 streak earlier in the season not out of a Nobel gesture, but because they didn't want the distraction of him whining all week.
The guy is an amazing player, but he is the type of guy that you have to make sure you keep involved for reasons behind his play and talent.