Okay, “spotty” might be the wrong word. How about “intermittently superior”? I’ve seen Roethlisberger throw for 500 yards and 4 tds, but is anyone prepared to put him alongside Brady, Manning, Brees, or Rogers? No, and that’s what I think of when you mention “premier” QBs.
Yes, as a matter of fact, I am.
Not one of the QB's you mention would have his stats if they had his line. We already know what happens when Brady and Manning face an intense pass rush in a high-stakes game: they lose. Peyton's loss is particulary instructive, since the "Spotty Roethlisberger" outperformed him in that game. Drew's QB rating is not much different from Ben's. We'll see how durable Rogers is over time.
But not only would I would put Roethlisberger "along side" them, I would not trade Ben for any of them. And neither would Mike Tomlin.