Spiderman 2: Eh, not bad. Not bad at all. The effects when Doc Ock (Alfred Molina) is traipsing off, using the sides of buildings... Fantastic! Rippin' off car doors? Awesome! Carryin' off screamin' women? ... You get the idea. :-) I didn't notice any mistakes (and, yes, unfortunately I had caught some headline about the "many" mistakes in the movie's effects before seeing it).
Now that I've visited New York, I recognized the Flatiron, a.k.a. the Daily Bugle building, :-) right away. My wife assures me that they used it in the first one too. Amazing, how the city comes to life in movies after you've been.
This one was slower, though; no question. Overall, I certainly got my money's worth, but the first one was a better package.