I am in the wrong audience for Elf. I think the movie on which it is based is Just Okay. I stopped enjoying Will Ferrell movies at some point after Anchorman, unless you count the Producers movie musical, in which case Ferrell was about the only thing I found worthwhile. And when it comes to Christmas music, I'm less likely to get in the festive mood and more likely to rant about how all the recordings are Baby Boomer-era. So perhaps it is fully chalked up to low expectations, but I actually kind of enjoyed the musical version of Elf.
Elf The Musical takes it's cue from the original film at nearly every moment: it's still a story about a supposed orphan (Avenue Q's Jordan Gelber) who is brought up at the North Pole among elves before taking a trip to Manhattan to unite with the Father he never knew he had, all the while falling in love with a girl (Leslie Krtizer) who simply needs to find her Christmas spirit! The plot is a near-copy of the movie, save for the obvious changes you'd expect with the constraints of the stage. Which means, like many film-to-musical adaptations, characters will undoubtedly break out in song to belabor a minor point that was three lines long in the film.
But bookwriters Thomas Meehan (Producers, Hairspray, Annie) and Bob Martin (Drowsy Chaperone) seem to understand the way these bland adaptations are expected to transpire and have decided to just go with the flow, all the while peppering the script with as many jokes as possible (many of which are pretty damn funny). Matthew Sklar and Chad Beguelin's songs are serviceable and while they definitely have a Christmas feel, they are not quite as witty as the book that surrounds it. In fact the need to "get a song in" often stops the show dead; an example is one song where Gelber's Buddy teaches Jovie the importance of singing, which not only feels like the most generic showtune ever but also happens so early that she has no character advances or epiphanies for the other half of the musical.
The cast ranges from wasted (talented ladies Kritzer and Beth Leavel as Gelber's mother) to hysterical-but-a-bit-one-note (Gelber) to an unbridled joy (Wayne Knight, playing Santa Claus as a sometimes-narrator). David Rockwell's yuletide set evokes the North Pole, the Empire State Building, Central Park, and a how-did-they-do-that-onstage ice rink that I can only presume was a very smooth telfon-y plastic that can be "skated" on. I haven't seen Grinch, White Christmas or A Christmas Story's musical adaptations so I can't speak much about comparison, but if your family chooses Elf as the Christmas musical they see this season then by all means go, let go of your expectations, and have a great time.