Consistently in the biggest games? Not great D's. NE won b/c of Brady and the O, the D was good enough just like Indy's was but their O couldn't play in big games.
How did the Steeler's defense do in the last few superbowls? How did the Ravens top defense last year look in the superbowl? How about the Bears top defense against the Colts? Not very well did they? You know why, because they are playing against another top team, and top defense or top offense means nothing other then end up winning the game.
I don't know how you could already forget how those SB Patriots teams won already, it has not been that many years for you to forget, so I guess you can hopefully try to remind yourself how those Patriots teams won in the regular season, play-offs, and superbowl, or you could continue to deny just for arguments sake...up to you.