In the last 16 Super Bowls, 11 of them had a 2 week wait, and 5 had only 1 week.
For the one week breaks, the point differences were 27, 3, 7, 17, and 1.
For the two week breaks, they were 11, 3, 3, 27, 15, 7, 14, 10, 23, 35, 13.
Making the average point differential for 1 week break games 11, and for 2 week break games 14.7. Both about a 2 score game.
The one week fans will say "You conveniently left out the 17th super bowl (49er 55-10 drubbing)" which would skew my two week differential a little higher.
The two week fans will counter, "but look at recent history, the last 3 games of 2 week break have an average of 5.67 points between them, while the last 3 one week games have an average of 12.3 points.
Conclusion: You can manipulate numbers to say whatever you want, and I wasted my time trying to figure out some sort of correlation. Please feel free to extend my research to the rest of the super bowls, perhaps that would be more telling than my 16 SB snapshot.
EDITED: I had the numbers mixed up a little in my hasty data collection so I made the necessary corrections. Still about the same result though.