Long time Steelers Fan here.
RE: Tomlin - This thread sums up a lot of my feelings on Tomlin in general.
He has had a hell of a successful career. 18 consecutive non-losing seasons to start his career, taking teams that were by far not the best at points and getting them to the playoffs (Rudolph/Duck, Pickett/Rudolph/Trubisky eras). I'd even argue this year was more of a success than it could have been with having only one legitimate receiving option in the entire offense.
However, he has also had some years (the killer Bs???) where he had the talent to blow the playoffs away and he couldn't put together a game plan to get them over the hump. He consistently makes weird play calls (fake punts on 4th and 10 with the score tied going into halftime type JV plays) and it does often feel like he's out coached by his contemporaries (Harbaugh, Payton, McDermott, Reid.)
The 2009 SB win was mostly Cowher's team running mostly Cowher's offense and Dick LeBeau's defense.
So, looking at his record, 2011 and 2017 are the only years where you can argue he actually took a team of his own making anywhere worth talking about in the playoffs. Controversial on a NE sports thread, but 2017 should have been another SB year if the refs had eyes on the Jesse James catch. But sprinkled in you've had some wildly awful times (especially in the last decade.) The 11-0 to 12-4 ending with a first round loss to the Browns? The first round loss to Tim Tebow? The first round loss to Blake Bottles and the Jags?
I love the guy, I have been a long time defender. He's a HOF coach, would be immediately snatched by another team in the league if we dumped him, and would continue to go on and have success there - maybe even more success with a different team, environment, division, GM, etc. But this year (even despite what I think was overall a successful season given the offense,) the manner of the collapse and the team's showing in yet another first round loss has me for the first time thinking we ought to consider moving on in Pittsburgh.
At the end of the day, Mike T. hasn't had playoff success in close to a decade. If I were to draw a coaching comparison, it wouldn't be Jeff Fisher, it would be McCarthy's Green Bay era. He was great when he was great, but by the end it was time for him to go.
Vrabel? I'd be psyched to get him in Pittsburgh (young guy, room to grow, hungry like I feel Tomlin was in the beginning.) So I voted Tomlin/Tomlin because I would have wanted the rest of the league going after him while we brought in Vrabel.