lol said it before, say it again, glad my club didn't have a wad of cash and a few latte joints around the training field... the bloke is a short term winner, long term loser for any club psyche. He'll come in, have some great games, but then his mouth, his ego, and his lack of adult type control will start to infiltrate through the club's culture, and you'll start coming up with divides... either player to player divides, or player versus staff divides.
He's exactly the type of bloke you do not want at your club, irrespective of his prowess as an on field athlete. I would back the Roosters to make the finals next year, he will be passionate, he will play hard, and he will be a good on the field contributor, but beyond that, I'm not so sure as his own personal agendas and lack of man management and attitude control start to cause culture problems. For mine, the Roosters were rebuilding nicely, and I think would have achieved more long term success without Mason.