Ben Stiller proves he can act - but can he save this film?

Noah Baumbach's "Greenberg" is, once you get past the unlikelihood of the premise (family goes on "vacation" for apparently 6 weeks! and leave their Hollywood Hills mansion in the care of the brother just out of a mental hospital) an incredibly realistic and astute portrait of two troubled, needy characters - 40ish exmusician and mental patient Ben Stiller and 25ish personal assistant played by the little-known (to me) Greta Gerwig (?). I've not been a huge Stiller fan, but in this straight-drama role he's excellent, and Gerwig is if anything even better, vulnerable, needy, insecure without being cloying or annoying or supercute. I could believe every second of their interaction, as they fall in and out of each other's lives, and every word of their dialog, which is quirky and quick but feels as if spoken by real people not by screenwriters in a seminar. All that said: I also felt that 90 minutes with these needy people was about 80 minutes too much. Baumbach is a really talented director and writer, but it's no wonder that his movies since Squid & Whale have been commercial disasters - there's nothing about these people or their world that we like or even want to like. They're people whom we might know and recognize - but would probably avoid or ignore. Greenberg is far better than the earlier Margot at the Wedding, perhaps in part because Jack Black proved he can't play straight drama and Stiller proves he can, but it's not a movie in which any character grows, matures, changes, or surprises. We may feel sorry for the characters, but the sorrow doesn't rise to the level of pity or of empathy. We're glad to see them go.