Seymour Duncan Black Winter 7-String Set

I bought these PU's for a Jackson JS32-7Q and the amount of tone and clarity, especially from lower tunings is a huge improvement compared to the stock pickups.

While they are very high output pickups, they do clean up nicely when you back-off the volume. You can also get some more variation to the sounds by wiring the in-between-positions of the 5-way switch to for example inner and outer coils which are good for cleaner tones.

I really don't have anything bad to say about these. After checking out demos in youtube, the sound was pretty much what I excepted it to be.

The Black Winter pickups really do what they're supposed to do for me - and I'm happy for this.
The bridge pickup has nice clarity for high-gain chugs.
The neck pickup works well for singing leads.

The pickups have a pretty low noise level - very nice for high-gain playing.
The single-coil settings do sound single-coil'y - comes useful every now and then.

Guitar pickups are much a matter of taste, possibly sound different in different guitars, and so on, so it's difficult to give recommendations or ratings - but my experience has certainly been positive.