There are games where that OL got dominated, run and pass. The 2 most recent were the Jets game and the 2nd Seattle game (though they did rebound in the wildcard game and gave back what they took in the 2nd Seattle game...Whitworth helped with that).
One good explanation for why the passing game altered so drastically this year to a ball control game was to account for the OL. That had to do with RB pass pro too, except of course for Brown.
I would say overall, adding the ups and downs together, if you watched them, they came across as a solid OL. Well coached to maximize strengths and minimize weaknesses, which is what we would expect from Kromer, but the games where they got exposed, there were no answers on the field.
Given all that I would rank them around 12th give or take.
So, solid overall. As we clearly saw, they got beaten up at times. Some games they dominated. They were not consistent getting the run going (look at the Tampa game) and they sometimes came across a defense that could take them on as both a running and a passing team (2nd Seattle game, Jets game, both SF games....and to a lesser extent the Giants game).
I would not rank this OL over the Saints, Colts, Titans, and Ravens, among others.