I haven't piped in about Rex Ryan yet because I have mixed feelings about the hire. He certainly wasn't my favorite HC candidate, I must admit. Ultimately, I believe it's about the total chemistry of a team that matters most, and some coaches, front offices and player personnel just don't quite fit together well. Also, people change and grow from past experiences and that goes into the mix. If you think back when Marv Levy was the head coach, they called preseason "Club Marv" - and it worked for that team at that time. Yet, I don't think that philosophy would work, let's say, with today's Patriots team, where the players are cogs in the Belichick machine.
The reality is that no one knows how this will end up, but we can hope that the match is better with second-time Rex and today's Buffalo Bills under Pegula's reign.