John Warrender’s review published on Letterboxd :
As if foisting the noisome Hangover onto the world wasn’t bad enough, screenwriters Jon Lucas and Scott Moore also poured this fetid waste over the heads of the 12 cinemagoers masochistic enough to sit through two hours of Jason Bateman robotically saying, “I’ll ruin that bitch” over and over again. I'm no prude, but this miserable fashion for R-rated comedies triggered by the success of Judd Apatow’s recent adult-themed movies has completely lost sight of the fact that his movies understood and sympathised with humans, and were more frank than profane. The Change-Up is a miserable experience by comparison, bereft of compassion or empathy, as phony as any knock-off Prada handbag, as mechanical as any mass-produced soon-to-malfunction off-brand gadget. The formula here is that single Ryan Reynolds and married Jason Bateman swap bodies and see how the other half lives; Freaky Friday for Nuts readers.
The least director David “Wedding Crashers” Dobkin could do is slot the relevant story parts into place with some form of competence, but he can’t even keep the characters consistent. Reynolds’ sex-mad slacker begins the movie as a foul-mouthed loser; an hour later, in Bateman’s body, he’s a noxious, sociopathic piece-of-shit who should be euthanised. And don’t get me started on Leslie Mann and Olivia Wilde, forced to be little more than signifiers of virtue and lust respectively. Sitting in a bath of cyanide-laced horse-manure would be preferable to watching this empty, cynical enterprise trail slime across the finish line.