Ok, people may think this is b@ll*cks, but I've found that P bass pickups tend to sound pretty much the same, and I've never really heard a bad one.
But Jbass pickups do seem to all have a different character. The worst I've heard were from an early 90's Fender (Japanese?) - very hard and edgy sounding, low output and did the bass no favours. Kent Armstrong (Korean made) replacements sounded very full and punchy (for the money) but still had a bit of harshness. DiMArzio (humbuckers) sounded great, good and honky, but not really the classic bright tone you'd expect form a J. EMG's are fantastic for a modern clear sound, but can sound much more traditional if you turn the tone down at least half.....
That's the ones I've played....oh and a SD Antiquity (bridge only). Easily the best sounding, most traditional etc but was pretty microphonic and hummed like a bee
BB