Everyone except Gordon in the regular rotation is a all-defense candidate and they have the best defensive coach around who makes his players give 100% every minute they're on the floor. And they're deep enough so that, unlike the Pistons, they'll be able to give 100% because when they get tired they'll have people on the bench waiting to take over.
Best defense in 5 years, sure. Best defense ever, no chance. As I said, they dont even have a case as being the best defensive team the Bulls have had. Jordan, Pippen, Rodman, Harper and co were just flat out better defensively. Honestly, there is no arguement when you consider that team has 3 players considerably better defensively than the best defender on their current team(whoever you consider it to be). It just isnt close and that Bulls team really cant match a lot of other teams.