British big-screen comedies have always lagged behind in quality when compared to British TV-series, and it's a bit of a mystery why that is. After all, a script is a script, right? To say that British films are weaker than British shows is a major understatement. UK comedies are usually terrible, even the rare successful ones like that mid-90s male-strip film or "Four Weddings & Hugh Grant's Bloody Funeral" are average at best.
MOFOS isn't that bad, but there is a sense that it could have been much better, in spite of the overly simplistic and cretinous premise. A decent budget and a cast of well-knowns indicate that a measure of optimism existed about this project. However, it's once again the script that is to blame. I have no idea why certain people got excited over this script. Nevertheless, MOFOS is watchable, rarely dull, and even provides one or two chuckle-worthy moments...
I'm sure that had Ron Howard or Peter Bogdanovich made the same exact product, MOFOS would have been praised and praised until our collective ears bled away.