CONTAINS SOME SPOILERS AND GENERAL WHINGING
In precisely the same way that numerous idiots declared that Daniel Craig could not possibly be the new James Bond because he doesn't look like Sean Connery (or the character described in the books written more than half a century ago), so other idiots declared that Tom Cruise should not play the lead in the film adaptation of Lee Child's novels. Reacher is six foot five, Cruise is five foot seven, therefore This Must Not Be Allowed. A seemingly unavoidable piece of logic blown away by one simple fact: it's called acting. Playing someone you're not. No-one expects demonstrably Danish characters such as Hamlet to be played exclusively by Danish actors, no-one would suggest that a King should only ever be portrayed by someone no more than fifteenth in line to a throne. Maybe they'd have liked it better if they'd given Vin Diesel a wig and platform shoes (he's still too short). If you want the Reacher of the books, read the books. They're not a sacred text that cannot be adapted in the slightest detail for the screen.
How it compares to the books (specifically One Shot) I wouldn't know. But as a movie, Jack Reacher is perfectly decent: a solid mid-range action thriller directed by Christopher McQuarrie with crunchy enough violence to warrant a 15 certificate (it's been trimmed by a few seconds to get a 12A, though I personally feel it's not enough) with plenty of fighting and chasing and gunfire to make it a cheery Boxing Day release. Indeed it starts off with a public shooting in which five random people are shot by a marksman with a rifle: the suspect is quickly identified and arrested, but despite the overwhelming evidence, is he actually guilty? His former Army colleague, ex-military police investigator Jack Reacher (Cruise) shows up and delves into the case....
It all rattles along efficiently enough, though at 130 minutes it's on the long side; it looks superb (Caleb Deschanel was the DP), Joe Kraemer's score has slight hints of Jerry Goldsmith and Howard Shore, and it has a pleasingly old-fashioned feel to it, ditching the current trend for action sequences and car chases to be edited down to an incomprehensible blur, and nicely written with some smart one-liners. And it's cast with slightly unusual choices: Werner Herzog is suitably villainous, though a mass public shooting seems an odd way to go about his stated aims which actually seem fairly modest. More fun is Rosamund Pike's wide-eyed and slightly dizzy exasperation which almost seems to have carried over from Johnny English Reborn. Nice to see Robert Duvall again for a few scenes as well.
Sure, it's not as much romping fun as last year's Christmas Cruise (Mission: Impossible: Ghost Protocol): it's more downbeat and less of a crowd-pleaser. But as a mid-range thriller that's more about investigating and deducing than it is about blowing things up and shooting people, and more about telling a story than about ever more ludicrous stunts and special effects, it's good to see and with luck they'll make more of them. Well worth seeing.