(EW.com w/the pic ... and a bad review that spends way too much time talking about something that doesn't really matter in this movie ...)
In that linked review, much time is
*Whaddaya need that for, Dude?
Another complaint about FSM is its derivative nature, as it harkens back to all those Judd Apatow/Seth Rogen comedies. And, well, it does, with the same rhythm (and, in many cases, the same players). So it's not wholly original in its execution. But that's not the point.
What separates FSM from the crowd (and this goes for all comedies) is its spot-on look at relationships. Good ones, bad ones, all the interested parties, everything. Unlike Knocked Up, it doesn't cop out with the phony, who-could-believe-that? ending. Unlike Wedding Crashers, the main antagonist -- the dude who's with the main dude's girl -- isn't a total cookie-cutter a-hole.
And here's the most mature part: Sarah Marshall (the Segal character's ex, played by Kristen Bell) ain't exactly a saint, but she's not a total you-know-what, either. She has her problems. So does Segal's character. So does his new love interest (Mila Kunis), Sarah's new love interest (a mostly funny but sometimes over-the-top Russell Brand), the probably gay guy who is obsessed with Sarah's new love interest (Jonah Hill, hilarious as always), the innocent virgin who is trying--well, you get the point.
Which makes it well worth the time, even if the laughs -- albeit hard* -- aren't as frequent as in other comedies of this type.
*This includes one of the funniest lines in years, though, uttered by Paul Rudd (as an airhead surfing instructor). Let's just say it's got something to do with carpet, but not drapes.