I hate it when the Green Bay Packers lineup with six offensive lineman. While some teams like to use a tackle eligible as a receiver in short yardage situations, it's not common under Mike McCarthy. I'd rather he leave in a full back or tight end, someone that might sneak out of the formation as a receiver, and give the defense another player to worry about.

Football Outsiders confirmed that it's not a formation used by many teams:

The Raiders were one of three teams that used six linemen more than 100 times. Oakland also was the best team in a 6OL formation, averaging 6.2 yards per play. 

It doesn't appear that the Packers even gained a yard in their four attempts with the six offensive lineman formation. It is interesting that the some teams relied on it, while most teams averaged under one attempt per game in it.