Too good to be true, this. Paul Giamatti, Kevin Spacey, Rachel Weisz, Miranda Richardson and Kathy Bates, plus Vince Vaughn reteamed with ‘Wedding Crashers’ director David Dobkin. Way too good to be true. Early on, Vaughn’s face-smashing donnybrook with an army of charity Santas bodes well. But he’s on autopilot here, rolling out his patented hustler-with-heart schtick as narky Chicago repo man, Fred, who’s little brother happens to be St Nick. Tough to blame Vaughn: slaloming between gooey seasonal cheese and near-the-knuckle sourness, this Christmas comedy struggles to stir knockabout kiddie fun with spiky adult themes of resentment and sibling rivalry. Lost on the wrong side of ‘Elf’ and ‘Bad Santa’, the script sleighs Fred to the North Pole to help his brother with the Yuletide push, hurdling reality checks with all the grace of a three-legged reindeer. Big laughs go missing and about 30 minutes should have been cut like deadwood– preferably Weisz’s rub-a-dub London accent and Vaughn’s ‘dancing’. But there’s no beating that cast. All sausage fingers, frazzled hair and morbid obesity, Giamatti is the first Santa to admit to acid reflux and sleep apnoea. No guessing if Spacey’s glacial contempt is simply for his role as an efficiency expert trying to shut down Santa – either way, it works a treat. What’s more, Dobkin’s film is lit up by a couple of genius scenes: first, a siblings support-group attended by Frank Stallone, Stephen Baldwin and Roger Clinton; second, a superb in-joke triggering Spacey’s redemptive thaw-out, stoking a festive glow against all the odds.