Not that it really takes much to be better than Death to Smoochy (which was really "Throw Momma From the Train" with Barney), but this movie is quite a bit better. It's more like "Throw Momma From the Train" in an apartment.
The movie has several HILARIOUS episodes dealing with Ben Stiller and Drew Barrymore as they try to deal with and plot to kill their upstairs tenant. The movie had some GUT-BUSTING parts where I (and the rest of the theater) couldn't stop laughing. [One of those times where you laugh so hard and loud you miss the next 30-60 seconds of dialogue] The performances were great, especially the old lady and Ben Stiller. Drew Barrymore seemed to be miscast at first (or at least not a good match for Ben Stiller), but when things started picking up, she played evil pretty well (thank you, years of recklessness).
The end of the movie was a let down of sorts, as the ending was sort of abrupt. It dragged for the last third, but by the end had wrapped up for the most part with no loose ends. In my opinion, this movie was better than Smoochy, but doesn't hold a candle to THROW MOMMA. I'd still give it 8 out of 10. I'm definitely going to purchase it on DVD when it is released.