I'm not convince McDermott can get us that elusive championship. But I'd rather be gnawing at the heels of one, rather than take a chance with a new HC and likely other coaching changes. It could be very risky, depending on the coach. I don't like the possibility that the floor could drop out. And it's not just the coach, it's Allen and the rest of the team. They would have to get comfortable with new plays and a scheme.
Whenever I think of this topic, I think of the Steelers with Bill Cowher. He went a long time before finally getting a Super Bowl. I remember a lot of fans wanting his head on a platter. Granted, much of that was during the "Slash" years, but the team stuck it out and he got his QB and a SB.
I'm doubtful I'll ever see a Super Bowl. I have some stats that have me thinking this way. But I'm will to stick it out. Just don't like the risky alternative.