Bad. He's got the tools, but Swihart's problem is that he's not proficient in using them. He just doesn't play like he's used to catching, and for the catching position that's particlarly bad. I think it's safe to say that Swihart's bat is maybe 2 years ahead of his glove, and he'd have to do some learning on the job to become a really proficient catcher. Then again it was also safe to say that about Mike Piazza, so he could still become a great catcher. but it's unlikely this team will invest the MLB playing time to allow him to learn his position on the job, which is a situation his bat has almost forced him into.
He'll probably wind up traded to some small market team that can let him develop through some grind years before he needs to really compete at the position. Maybe even wind up a star player for that team. If he stays in Boston though, I honestly think Swihart's days at catcher are numbered and he'll be moved to some other position where they have a major talent gap to take advantage of his advanced offensive approach. The Sox MO so far has been to want to pair a veteran with a young guy, and when it comes to catching, CV is their guy so they'll look for a Hanigan type, or even re-up Hanigan himself, rather than having 2 rookies catching if it can be avoided..