Not sure I like the term efficiency when describing our current offense. Total yards is very good certainly but it would seem to me that efficient offense would be scoring a higher number of points per game and points scored per yards gained or something. Our offense seems, in some ways, to be rather inefficient in the sense that we are gaining lots of yards but not scoring at a very high rate. I would not think this year's offense is very comparable to some of the high octane offenses of the past referenced.
It seems likely that at some point, with more refinement, development and additional talent and repetitions, we could very well enjoy something approaching the great offenses of the glory days. But we are no where close at this point in my opinion. Some of those great offenses hardly every punted and the punter was nowhere near the household name of our current ones.
I don't know the numbers and am not going to bother to search the records, but I would tend to guess that college football today has a much higher average offense yards per game across all teams as well as more scoring that 20 or 30 years ago.
Nevertheless, I am quite excited to see the dramatic improvement in our offensive output this year - we surely have a much more powerful and effective offense this year than in the past 6 or 7 years at least. We will only get better if we can build up the O line and add more skill players across the board.