Ok folks - I have finally had the time to put the Peacemaker bridge (with a Mule neck) through some paces, and here are my thoughts.
As a background, I play mostly 90's and 2000's pop, rock, punk, and hard rock with about 20 paid gigs per year - so not a pro. I have gravitated to lower output pickups over the years as I love the dynamic range and lower compression. My current faves with BKP are the Mule, Abraxas, True Grit, and the Polymath. I have also been a fan of Black Stone Cherry and their southern hard rock sound for well over a decade. When I heard that Chris Robertson was getting his own signature pickup, I was stoked. I installed the Peacemaker in a mahogany body/maple top Music Man Axis Super Sport (E standard) and tested with a Friedman Wildwood 20 amplifier and the BE channel with gain set to 5 and master on 4 - a great overdriven modded Marshall tone.
On paper, it looks like Tim and the team have taken lessons learned from their PAF research, and the separate development of the Polymath, and combine those principles to the Peacemaker. This results in extremely tight and articulate, vintage voiced, lower output humbucker that can handle very high gain.
The Good: The Peacemaker has excellent note separation and overtones - very musical and articulate. The dynamics are such that you can go from mean to clean with just pick attack on your picking hand and rolling back the volume can get you just about anywhere you need to go on a single amp channel. As expected with this output range, there is very little compression and palm muting is tight and percussive, even at lower gain settings.
The Less Good: My biggest issue with the Peacemaker is the low end. It is like there is a high pass filter at 120Hz with a steep roll-off. This can be compensated with power amp depth or post-distortion EQ settings. I shouldn't be surprised since much of Chris Robertson's music sits in the land of drop C. The bottom end felt better when I went into drop D, but still felt it needed to be compensated with EQ. Additionally, because this pickup has so little compression and is so highly articulate, it will be unforgiving for a lot of players.
Verdict: If you need a vintage-voiced pickup for detuned rock (Drive By Truckers), hard rock (Black Stone Cherry) or even metal, this is an excellent option. I A/B'd the Peacemaker with the Mule, and man, I do think the Mule can handle more gain than many folks will give it credit - the Mule is truly a PAF masterpiece and in this context prefer the Mule A4 magnet over the unoriented A5. If you can less about the vintage voice, I find the Polymath to be more balanced, particularly in the low end and ultimately is a more versatile example of the unoriented A5 magnet. I would love to know what Chris Robertson felt either the Mule or the Polymath were lacking when he and Tim were developing the Peacemaker.
All in all, you can't really go wrong with anything from BKP. Get out and make some music! Rock on.