Dom Capers certainly has done great things in his career and if he retired today, he'd retire as one of the better defensive coordinators the league has ever seen.
That said, I don't think it's any great leap to say that the players in GB have tuned him out a bit and maybe Dom isn't the guy that can get the best out of this current crop of guys. I think it's time for a fresh look there.
As for McCarthy, I think he's okay, but when you watch the Pack without Rodgers, you realize that Rodgers is much more responsible for McCarthy's success than the other way around. Aaron Rodgers would make a lot of coaches look much better than they do right at this moment, and McCarthy just happens to be the lucky guy that hit the lottery.