One thing about 51 that's sitting nice with me.... no Jet stains.
The "first dynasty" of 2001 - 2006 were defense-first teams; the team won in 2001, 2003, and 2004 largely on the back of its defense. The offense had varying degrees of success, with 2004 being its best, and all the while Brady slowly transformed into a great QB.
Since then, the Pats have been offense-first. Many people were concerned that we were turning into the Colts, and there was definitely truth in that -- like most offensive juggernauts, they eventually got stopped by good defenses in its playoff losses in 2007, 2009 (understood it wasn't as good of an offense), 2010, 2011, and 2012. The Pats did not have a defense that could pick up the slack, not even in 2007 which was sort of the last-gasp of the old teams. There were concerns Belichick lost his touch as a defensive guy and couldn't adapt to the new Polian era.
Belichick finally got a good defense again and won a Super Bowl.... after bringing Jet-stained Revis in as a mercenary. We laugh about how Revis had to go to the Pats to win a Super Bowl. But some have said that the Pats couldn't win the Super Bowl without resorting to bringing Revis in. Revis himself tweeted that prior to the 2015 season (he then deleted it and claimed his account was hacked).
2016 proves to those doubters that BB can build a defense again. The entire secondary minus Rowe is home-grown, and Rowe was an opportunistic trade, not major FA signing. And from our perspective, we can watch modern Super Bowl win and not feel like we sold our souls seeing Revis out there, like we may when watching 2014 highlights.