I haven't read the Mordecai Richler novel that Barney's Version is based on, but it's not hard to tell that the movie has been condensed from a much larger narrative. The sprawling character study is entertaining and often moving, with a great lead performance from Paul Giamatti, but its various elements often feel disjointed, like there's some connective tissue that got lost in the translation from page to screen. It's no surprise to learn that the novel relies on first-person perspective and a question of narrative reliability, as the aging Barney (suffering from Alzheimer's disease) tells his story (his "version"), while his son offers corrections.
That whole device is missing from the movie, although Barney (Giamatti) still suffers from Alzheimer's disease in the present-day framing sequences. Without the narrative uncertainty, it instead comes off as a little sappy, although the movie avoids overplaying the cliched memory-loss moments too much. The main draw of the story isn't that part, anyway, but the flashbacks to Barney's life as a younger man, first as a vagabond in Italy bumming around with his drug-addict aspiring novelist best friend Boogie (Scott Speedman) and marrying a troubled free spirit (Rachelle Lefevre, underused). Barney then heads back to his native Montreal, where he becomes a TV producer on a trashy soap opera and marries a shrill Jewish stereotype (Minnie Driver). Driver's character (who's never named) is pretty one-dimensional, and Driver's inscrutable accent and hammy mannerisms don't help her develop further.
It takes almost half the movie to get to the heart of Barney's story, his romance with the lovely and compassionate Miriam (Rosamund Pike), the love of his life and mother of his children. The bits with Driver are sometimes funny, thanks mostly to Dustin Hoffman's goofy performance as Barney's uncouth dad, but Barney's relationship with Miriam has real depth and emotion, and the slow demise of their marriage is the movie's most effective and resonant plot point. Pike does a great job of conveying Miriam's allure as well as her intelligence, and she convincingly shows how Miriam could fall for this schlubby older guy. She then just as convincingly shows Miriam's heartbreak as their relationship falls apart. A good hour of the movie is a wonderfully affecting portrait of the arc of a relationship, but it's a little lost amid all the other stuff (including a tacked-on mystery about the possible murder of Boogie). A novel can easily encompass this kind of diversity in taking stock of one man's entire life; the movie struggles to do the same, although it comes out mostly ahead.