It's no secret that I do not like George Kottaras. I can give him credit, at times, for clutch hitting and stuff... not easy, considering he's kind of a tool.
But, no, he does not need to be in Boston. Sure, you can look at his numbers and say, hmm, okay, not bad. But there is no statistic that says yes, he's doing his job as a catcher, but he looks like shit doing it. You can have a .996 fielding percentage, but it doesn't say that the third baseman is killing himself trying to stab line drives. There's clean fielding and there's shit luck.
I have seen him play in person over and over and he is not a major league catcher. I have EYES. I have seen him hack and fumble and it is not easy for him. If he doesn't have it down by now then it's not going to happen.
Dusty Brown isn't Yogi Berra or anything but he doesn't appear to struggle as much. If I had to choose, it'd be Brown. I'm not in love with him, but he's better than GK.
David Ross is gone, by the way. I forgot to tell you that.