PFF (who watch WAY more football than the average fan) rank the Packers' oline as 3rd best in the NFL.
Honestly though, I understand that as a fan it can be easy to make every weakness a catastrophic problem, but having ONE problem position on the oline is a blessing in today's NFL. Have you looked at some of the other olines in the NFL? Again, I don't look at PFF ranks as absolutes, it's not like a thermometer; PFF ranking them third doesn't have to mean they are exactly third. I would, however, take it to mean that the oline is REALLY good compared to the rest of the NFL.
I also can't find any now, but there have been a few articles discussing the limited amount of pressures that the Packers oline has given up so it's not just PFF.