I really don't like EMG's, but it's just a matter of personal taste. I would never say they're cheaply built or something like that, I just don't like the sound. For some reason they sound too compressed to me. I've always been in love with Seymour Duncan, they sound more dynamic and less punchy. But then, I haven't tried all models produced by EMG, I might find one that makes me fall in love
He pretty much nailed it, they are more compressed and punchy. I just bought a Spector Euro 4lx and it has emg pj's in them and frankly I am IN LOVE with the sound. There very thick and bouncy and the highs and mids are not harsh in anyway and last night at practice they fit so well in the mix. It cut through nicely but not obnoxiously standoutish, and still filled the role of what a bass player should. Its up to you and you'll find whats most pleasing to your ear, but as paranoid said, emgs are more punchy/ rounded in your faceish and passives(be it duncan or whomever) are more open and "dynamic"