Good post. I will disagree about Browner just a little bit.
BB was more susceptible to a double move. He's fast, but not quick. That's how WRs got behind him. He would also get beat by guys like TJ Hilton that are just straight burners. If they could get a clean release, and the QB had a really good throw, they could get him, but Browner's length made it hard to drop in.
Browner was probably the best in the league at defending screens to his side and blowing up run plays. Watch the games; teams honestly just quit throwing screens to that side as well as any sort of sweep type running play. Browner was also excellent at comeback routes because of his length. I'd disagree about his pursuit. Browner was great at running down plays, and took excellent cross field angles. Look at that play on AP; he caught up to him when Peterson was about to score.
Maxwell, conversely, is quick enough that he can recover on double moves, but he gets beat on comebacks. He also tends to play like the WR is heading to the sidelines and gets beat inside at times. He's also great at run defense, but he's not the hitter Browner was, and not as physical getting off blocks (who really is at CB ?). Maxwell is actually better at punching the ball out (which is saying something).
Under the new rules I think Maxwell is better. I honestly think Simon might be our best CB in 2 years. He's looking that promising. I'd love to keep Maxwell, but I don't think we can afford him next year.