The opt out makes it make more sense for him but still feels like his agent capitulated, and to be fair when you're a pitcher, sometimes the client knows best as you pointed out he had tremendous downside risk.
Feels like he left a lot of money on the table. That's a 2019 type extension... Quick maths say he puts up a conservative 15 WAR over the next 6 years that's still only like $13/million per win over replacement. If he balls out and puts up like 25 WAR Red Sox have one of the best ace contracts in baseball.
He seems like he's turned a corner. I saw his face today and personally I thought "looks like he's on the juice". Good, just don't get caught before you're traded.