Seymour Duncan Custom Flat SSL-6

Brent's take:

This is basically the flat-pole piece version of the SSL-5.  On the current Seymour Duncan site they claim a slight output boost for this pickup vs. the SSL-5, but I imagine that is comparing the two on the same guitar, which isn't quite apples to apples as you would normally use the SSL-6 on a guitar with a flatter fingerboard and the SSL-5 on a guitar with a smaller-radiused fingerboard (generally a vintage or vintage-styled guitar).  

From the manufacturer:

"application

Beefed up true single-coil for warm instruments. Perfect for Texas blues rock, classic rock and heavy rock.

description
Beefed up true single-coil for warm instruments. Perfect for Texas blues rock, classic rock and heavy rock.

complete setup
Calibrated set available with RW/RP middle pickup. Many players use an SSL-6 in the bridge position with vintage output pickups, like SSL-2's, in the neck and middle for tonal versatility.

guitars
For heavier and brighter-toned instruments with ash or alder bodies. Works well with maple or rosewood fingerboards.

available mods
Reverse wound, reverse polarity (RW/RP) middle pickups for hum-canceling in positions "2" and "4" on the five-way switch. 

specs
Magnet type: alnico 5 rods, D.C. Resistance 12.9k

players
Duke Robillard, Mark Slaughter / Slaughter, Rafa Payan / Juan Luis Guerra"

Best videos/sound clips:

Johnny Hawthorne here is playing an SSL-6 in the bridge position of a Fender Select Strat.  Some great mid-gain tones here - sounds like "Summer of '69" - not too bright...good crunch...  He starts playing at 0:54.  

Basic video below put out by Seymour Duncan showing the SSL-6 off in the bridge position of a Fender Strat (looks to be a MIM but I can't be sure).  The player is John Patelis, and the amp he is using appears to be a Soldano Astroverb 16 1x12 combo.

Another SD video here; on this one the player is Nick Johnston.  Nick is playing a Schecter guitar through an Apollo Twin audio interface with the SSL-6 in the bridge and the Alnico II Pros (APS-2) in the neck and middle positions.  The song he's playing at first has almost a gypsy-like flair and the tones are mid-gain.  He then switches at 3:07 to a cleaner tone with no backing track and does a good job showing how you can switch from clean to a lead tone by modulating the guitar's volume.   

 Sean Rock recorded this video of his G&L Legacy with a newly installed SSL-6 in the bridge.  He goes for some more modern tones than the players above so I thought I'd include this video.  As a side note he talks until 6:20 so I'd recommend skipping ahead to the playing.  

Here's an odd setup that is well-mic'd:  an SSL-5 in the bridge with a SSL-6 in the neck.  The use of an SSL-5 or 6 in the neck or middle position is definitely more atypical, so I wanted to include this video.  He also has a switch that allows for the neck+bridge combo to be played.  Basic strummed chords used to show the tones.  Guitar used is a Fender Highway 1 strat with a 1999 MIM neck.  Amp used is the Silverface Fender Champ with a Jensen C8R speaker, and the setup is mic'd with a shure sm57.  Player is Ed Migliaccio.