As a 49er fan I can say this is an interesting situation. Purdy has obviously performed better than expected, but he definitely missed some throws and reads early in the game last week. Even the throw to Jennings late in the game was not a great throw(should have thrown it more to the boundary). When Jimmy G was starting there was talk that they were going to resign him on another 1 year deal and he had said that he would contemplate it. I get the feeling he kind of likes being a backup, but I don't really know. Anyway, I am also not sold on Lance, but I was never thrilled with the pick in the first place.
My thought is they stick with Lance and Purdy moving forward, though, if someone is willing to offer a nice pick for Purdy and they are able to resign Jimmy then I would prefer that.