That English dub has two serious flaws. First, they took out the two fun 70's J-POP songs, which really set the tone of the film, and replaced them with forgettable American songs written for the movie. Second, they inserted background music into parts of the film that aren't supposed to have music (e.g., when the mood is set by the sounds of the town, or suspense is heightened by only having the sound of the wind).

Edit: Also, Jiji (Kiki's cat) played by Phil Hartman has a completely different character from Jiji in the Japanese version.