Since end of October, we are averaging two goals against every game. To me that screams out that something is not right with our defence. Hladky, i believe, doesn't instill as much confidence from the team that Walton would do. Obviously, that's a subjective feeling, and appreciate that we are now up against 30m strikers as opposed to L1 strikers last season.
Walton, last season, was arguably head and shoulders (quite literally) the best keeper in the league, and was touted as possibly one of the best keepers outside the premiership.
I don't think McK will drop him, which i think is wrong, as no player should be indispensable.