Alex Smith is exactly as good as the team around him. If you have big playmakers who can make yards on their own after the catch or in the ground game then the offense is just fine against most defenses. When you run into a really good defense that doesn't allow gaps or much YAC he gets shut down and becomes a 10-17 point a game QB - which is why his playoff record is so spotty over the years. With the Jets Smith is somewhere between a 1 and 9 win guy depending on how much talent is layered in around him. Really he's probably a 5 to 9 win guy because the Jets defense and 4th place finish will keep them in a lot of games next year and they'll win some of them like they did this year. McCown is a completely different kind of QB, with more loft in his throws and more balls throwing to his guys. Basically same number of wins for the Jets while he is healthy - except it will be very hard to catch lightning in a bottle and get 9 wins and a playoff spot. This is because he's just not as polished as Smith and will have more than a few drives that turn on a bad decision or throw.