The other Bergman was "Smiles of a Summer Night". A nice comedy of manners, but didn`t do much for me. But as Imdb lists over 60 films under his direction, I`m optimistic there`s much to discover in the future. I mean the guy has such a tremendous reputation, that I`ll surely love some of his films...
If I go on another director I`ve seen only few films of, Carl Theodor Dreyer, there`s a similar situation. Saw Vampyr and Gertrud. The first i found mediocre, the second had phenomenal direction, but the film didn`t do much for me. But his "Day of Wrath" was imo great.
Anyway, I don`t judge directors but individual films, and some of my favorite directors have made mediocre films.