It's really quite simple: if you're a fan of the stooges then you'll enjoy this.  If you aren't a fan then you probably won't.

Let me start by saying the three guys they got to do Larry, Moe, Curly, Chris Diamantopolous, Sean Hayes, and Will Sasso all did a fantastic job.  Their performances are true homages to the real Larry, Moe, and Curly, everything from the voice to the speech patterns to the physical quirks.  It doesn't feel as if they're acting like the stooges, they are the stooges.  Naturally there's a ton of slapstick with the three guys beating up on each other and anyone who gets in their way.  If slapstick isn't your thing, then this movie also isn't for you.  Even if you're a fan of comedy and just want to laugh, the brand of humor may be a bit obscure because, well, the stooges are just odd individuals.

The movie actually doesn't make a hell of a lot of sense, but that's to be expected.  These three are dropped onto the doorstep of an orphanage as infants and they wind up staying there until they're grown men.  They take jobs as handymen but are still looking to be adopted (at 35).  I don't know the rules of orphanages but why they would still be under their control at 35 doesn't add up, but this is a movie where 2+2=17.  The orphanage is set to be closed in a month unless they can come up with $830,000 so, naturally, the stooges go to work.  So then they get involved in this murder plot where this chick wants to kill her husband who winds up being a kid who used to live at the orphanage with them.  And then Moe winds up as a star on Jersey Shore, and that part was awesome because he goes there and just beats the crap out of everyone.  

Lots of violence but it's all slapstick.  Some of it's gross.  A lot of it is funny.  The dialogue and direction of the stooges was spectacular.  I've seen a lot of the Stooge shorts and was looking for flaws, but these guys really did a bang up job.  Larry David's role as a nun was also really funny.  

Overall I enjoyed it.  It's immature, it doesn't take itself seriously by any stretch of the imagination, but it's also a terrific homage to the original stooges.  If you enjoy the Stooge shorts then you'll probably enjoy this.  If you're not a fan then I doubt this would be the movie for you.

Greg

Spot-on review.  My boys and I love the Stooges, and we loved this movie.

The only difference is in the shorts they were never forced to imbue the Stooges with any feelings.  In this movie they had to do it to create conflict, then we find that Moe actually had depth and cared enough about his fellow Stooges that he didn't want to be parted from them.  Again, well played.

The guy who played Curly has been a favorite of my wife and I in both The X-Files (Je Souhaite) and Best in Show.  He is hilarious.

As Greg says, this movie is feast or famine based on your love of the Stooges.  We (my boys and I) love them -- not the wife of course; she finds them revolting.