Very (and I mean VERY) hot pickups, especially neck P-pickup, bridge J-pickup is not that loud. Relatively bright and punchy, with nice mid-range growl, these pickups also provides wide dynamic range. They react really good on HOW you play. And they cut through the mix really well. You can adjust individual pole pieces according to your neck radius and also you have different wiring options (series/parallel) for wide variety of sounds.
But not every instrument will benefit from that powerfull pickups. I bought these pickups as an upgrade for my fretless bass, and they've been too much for it, too "greedy" for my taste, especially for fretless instrument with epoxy coated fretboard and nylon wrapped strings. I mean you still can dial sweet mellow tone with that volume and tone knobs, but then you just don't use those pickups for their full potential. So in the end I just kept em for future use, right now P-pickup (which seems to be just DiMarzio "model P") is working in my P-bass project (well, actually Harley Benton kit) - and it really shines there.
All in all - this is great sounding pickups with nice features.