Got my DiMarzio Ultra-Jazz the other day and installed them, along with some 500k pots, into my Squier VM fretless jazz. Nice! I happened to check out a sound signature of one of the members, hieronymous, and that is the sound I am going to go for. He says it's a Duck Dunn signature P, and I'm thinking with the split coil in the Ultras that might give me the flexibility to get somewhere near his sound. Or not, maybe some sound that is diferent and just as interesting. If you are thinking about upgrading to these and you have a Squier VM fretless, they are drop in - they fit great. They definitely have a different sort of sound than the stock Duncan Designed with the little 250K pots. Those pups and pots really have a meaty, big classic single coil sound to them. Another TBer suggested 500k pots with the Ultras as this really opened up the high end, so I went for it. I wanted to be able to blend the pups without the single coil hum and to see what humbuckers sounded like. Definitely a different sort of sound. Required a bit of routing the narrow cavity of the instrument, as well as some careful wiring and orientation of the pots. What you see in the photo of the control plate was the only way I could get it to fit back on the instrument. Anyway, it's off on another aural adventure exploring these pups.