Both team were stellar at the skills positions and top defensive teams. Man for man, the comparison is fun to consider. Undefeated Dolphins team was really good for a few seasons, too, and stacked.
I think the 85 Bears, 92 Cowboys and even the 62 Packers have to be considered as well. I tend to think the 49ers were a little better though then the Steelers. It's a real toss up. I would say the Steelers were more dominate in their decade though. 4 Super Bowls I think 6 years probably won't be done again.
The 85 Bears were stacked with 1st round picks (20 of 22 starters), and actually the Bears in general were like 3rd winningest team of the 80s. I was thinking more of a dominant team over several years than any one team in one season. Player vs. player comparisons - Jerry Rice vs. Lynn Swann, and that kind of thing. The Jim Kelley Bills made it to 4 straight superbowls and lost them all, which is a remarkable feat. I wouldn't say they sucked by any means, even if they didn't win.
IIRC, the matchup of the Millennium that NFL Films and ESPN did with the 60's Packers, 70's Steelers, 80's 49ers and 90's Cowboys had the Steelers winning it all. If drug testing were involved though, the Steelers wouldn't have an O-Line
