His contract, $147M for 8 seasons, was a bargain, "Manny being Manny" notwithstanding.
Definitely a big deal in 2004, less so in 2007. The 2004 team led MLB in scoring, but the pitching was 8th in ERA. In 2007, however, the team scoring was 3d in MLG and the Sox team ERA was 2d. Indeed, of the four WS-winning seasons (2004, 2007, 2013, and 2018), the 2007 team had the best pitching. Last time I checked, Manny Ramirez didn't throw a single pitch in the entire 2007 season and postseason.
Plus 2007 was a down year for Manny in the regular season. The Sox hitting stars were David Ortiz and Mike Lowell. In the postseason Manny hit the game-winning dinger in game 2 vs. the Angels, but the Sox pitching held the Angels to 4 runs in 3 games. In the 8 wins against the Guardians and and Rockies, Manny's hitting wasn't a factor either because the winning margins were huge or because Manny didn't contribute in the two close games, 2-1 and 4-3, against Colorado.
As for 2004, Ortiz had the big bat in the postseason, especially in the crucial extra-inning games 4 and 5 vs the Yankees in the historic come from behind ALCS. Plus don't forget the bloody sock guy.