As awesome as Fitz is (and make no mistake, he's arguably the best WR in the NFL), I question the wisdom of guaranteeing $50 million to a receiver when your have an uncertain quarterback situation.
"It breaks your heart. It is designed to break your heart. The game begins in the spring, when everything else begins again, and it blossoms in the summer, filling the afternoons and evenings, and then as soon as the chill rains come, it stops and leaves you to face the fall alone." --- Bart Giamatti, on baseball
Anecdotally, it seems that most of the potential Pro Bowl players that are Super Bowl teams beg off from the game. I'm not a big fan of playing on the same field, in case they tear it up or it rains or what not.