Both are gym rats that are one of the hardest workers on the team. Zach probably has more swagger than John, but I don't see that as a liability (to the extent he isn't doing too much and not relying on teammates). The biggest difference is John had nobody behind him on the depth chart to challenge him, whereas Zach has 2 high high floor QBs behind him nipping at his heels. Both Jaren and Baylor are a lot less vocal than Zach.