I've heard folks with the 5-Speed units argue both ways regarding the merits of Syncromesh, however, the 6-Speed folks almost universally argue for the Synchromesh. In my case, when I bought my TL, shifting into third gear was notchy, it would sometimes grind, and other times it wouldn't fully go into gear and would subsequently pop out. Synchromesh cured all of those ills immediately.