I had a set of Mules. Can highly recommend them if you like vintage tone.
My only advice would be: *don't*, repeat, **don't** go unpotted if you want to use it with any kinds of high gain.
Out of fear of missing out, my first BKP order went with unpotted pickups (for the full mojo)... well, the drawbacks are just not worth the supposed extra "mojo".
Noise and squealing issues were plagueing me the minute those were installed. I sent them back, and went for properly potted Mules.
No loss in "mojo" to my ears - but all the noise issues were gone...
...maybe just something to consider.
Sometimes, a bit of added (subjective) voodoo comes with too much of a trade-off somewhere else. IMO, going unpotted is just not worth the added restrictions that come with it.