Installed these in my 2009 MIA Fender Jazz bass.
Stock pickups were vintage ones and as I play in a metal band, needed something more "harsh".
These did the job, they brought more clarity to high mids and highs. Low mids are growly when needed and I won't even start about lows.
It handles everything you can throw at them.
Don't be fooled though. These are really versatile, can do great vintage tones as well, but with a nice growl to it.
I mainly play finger style and slap. These cut through distorted guitars and wall of cymbals like a knife through butter.
Have always used Seymour Duncan and these are top notch pickups.
Will buy again if I get another J type bass.