UP IN THE AIR is beautifully and cleanly shot by cinematographer Eric Steelberg. It marks, by far, the best turn yet from director Jason Reitman; sharp and clever and clear, it's a marked improvement from his previous films, Thank You for Smoking and Juno. It features two of the year's best performances—props, George Clooney and Anna Kendrick—and an impressive slew of other performances from Vera Farmiga, Jason Bateman, Melanie Lynskey, and Danny McBride. J.K. Simmons, Sam Elliott, and Zach Galifianakis show up, too, and if that's not enough, it also features a cameo by Young MC. If that last bit doesn't push the film to the top of your must-see list, then you are not someone I'd like to know.

Thanks to all the things listed above, Up in the Air is one of the better films you'll see this year. Thanks to its script—by Reitman and Sheldon Turner, loosely based on Walter Kirn's novel—it's also a film that isn't as good as it should be.

As a profile of a man—specifically, Ryan Bingham (Clooney), who spends nearly every day in the air, crisscrossing America and occasionally touching down to fire strangers whose bosses are too chickenshit to do it themselves—Up in the Air is nothing short of fantastic. Bingham's life is lived in first-class plane seats, generic hotel rooms, and soulless rental cars, and he's developed a philosophy to get him through it: "The slower we move, the faster we die," he says, and he's true to his word, shunning relationships, responsibilities, obligations. Bingham's matter-of-fact solitude sounds simplistic, but in Up in the Air—and as delivered by Clooney, coolly and convincingly—it feels logical, true, pragmatic. Bingham is lonely, but he accepts this; he has no home, but he neither needs nor wants one; he lives out of a carry-on, but he always has everything that he needs.

But this is Hollywood, and this is awards season, and it would be wise to remember that Reitman's previous films, despite flirtations with tougher stuff, eventually devolved into goofily chipper fables. What's more, there's little drama in watching a solitary man calmly fly from place to place, content with his lot in life; naturally, the first instinct a screenwriter (or, in this case, two screenwriters) would have is to give Bingham some relationships, some responsibilities, some obligations—to ground him, so to speak.

Up in the Air never completely stumbles, but as it grows further away from Bingham's original state and closer to the sort of movie you'd take your mom to over Christmas, it veers toward Jerry Maguire territory. The plot's machinery starts to show, the audience starts to be told things rather than shown things, and Bingham, despite his best efforts, becomes less of a character and more of a pawn. This can all be traced to a few other characters—all of which are female, and all of whom are more rooted than Bingham. He's saddled with the chipper, naïve Natalie (Kendrick), who he's supposed to mentor. He has repeated hotel dalliances with Alex (Farmiga), a fellow traveler who's up for one-night stands whenever she and Bingham cross paths. He revisits his hometown to attend the wedding of his sister, Julie (Lynskey). If you're guessing that somewhere along the way Bingham starts to question his loner philosophy, give yourself a gold star.

But even as the plot's gears and levers become apparent, Up in the Air never feels disingenuous or preachy—only, in small increments, increasingly less engaging. Reitman, though, keeps control over the melancholy proceedings, expertly capturing the details of Bingham's life—the faux hominess of hotel rooms, the sterile, retro charm of airports—in a way that's at once romantic and critical. Supporting characters come and go, Bingham keeps flying, and Clooney, funny and calm, holds it all together. Bingham never quite gets the movie he deserves, but he's worth getting to know all the same.