Looking at the defensive stats, there probably could be an upgrade for the Reds though do you want to sacrifice offense for defense? I think the catcher position is one spot in the lineup in which the offense can suffer a bit if that means you are going to get a stud defensive catcher. If you look at Molina, teams just shut down the run game when he is in the lineup. If the Reds have a catcher that nullifies the run game, it just adds a different dimension to the games played. This is actually an excellent breakdown of the best defensive catchers of 2010. It gets into the sort of advanced sabermetrics but it is well researched and well thought out:
So the guy suggesting Yorvit Torrealba actually wasn't that far off if there is a team looking for defense. If you look at Yorvit's offensive stats, he is a decent hitter as well so its not far off to say, in my opinion, that the Reds could seek him as an option if they want a decent hitter with good defense behind the plate. What surprised me is that Ivan Rodriguez is still getting it done behind the plate.