Loved it. Not as much as Boogie Nights or Magnolia, but I have a thing for "showy," I guess. I was surprised at how "small" a movie this was, considering Anderson's past work, plus Sandler's rep for broad comedy.
I'm really surprised Nick had a problem with the character of Barry, since I found the guy
extremely likeable and sympathetic. "Stealing" an abandoned piano and breaking something in a fit of rage are not reasons enough for me to dislike a character. Barry's been henpecked to an outrageous degree and is managing to suppress his rage as best as he can. I think he saves most of it for himself, something I can empathize with. But, I think, with sisters like that, an occasional window
has to be broken.

And I think saying this stuff is acceptable for a character in a certain kind of movie, but not in another, is missing the point a little. As Quentin Tarantino has defended True Romance as being a love story (complete with drug deals, pimps, the Walken/Hopper showdown, massive amounts of violence), I think this is a PT Anderson love story (complete with fits of rage, pudding, phone sex, etc.). It defies the genre, which is a GOOD thing, I think.
Also, mikah's complaints that it only shows a hint of things to come? This is also the hallmark of some of the best American short stories of the last 100 years or so. It's the small things that count. Considering the length of this movie, I consider it the short story or novella in Anderson's ouvre, with Boogie Nights and Magnolia being the full-fledged novels with more characters and closure.