About the business aspect? A player would have to be a moron not to listen to the advice of a good professional agent. I'm sure there is the occasional exception, some player with the business smarts to see a better option than the agent does. But every other time the player should STFU, play the game, and let the agent work out all the other stuff.
Look at Peters now. Making good bank, playing for a better franchise, and living in what most would consider a much better city. And the only down side is that some Bills fans don't like him. You can't believe he made the wrong decision.