I have both, and they are both great, in the same family for sound. The Geezer PJs do have a certain character in the low-mids or mids—they are a go-to do pretty much anything pickup set. Compared to the Geezers, the PJAX seem to me to be slightly flatter and smoother from high to low, perhaps a little more extended, darker, even, yet clear, to me they resemble the Geezers with a slight mix of what I hear in my Bart DC’s, that’s not meant as better/worse. I hesitate to describe “growl” as better/worse between them... lots of other factors for that.
I preferred the Geezers in EADG, either in E flat, and think the PJAX is the better choice in my setup for DGCF... Fender PJ basses, different models so not perfectly apples to apples.
I very much recommend using the EMG EQ, specifically with the right ABC balance control—the ABC for the Geezers/the ABCX for the PJAX—I think that was significant when I was swapping things around among instruments and trying things, noticeably better with the properly matching ABC.
Regarding the wish for a Geezer J set, check out the SD Apollo’s, which are very nice, especially with the matching SD 3-band EQ. Not a “Geezer” set, it is a J set and all, but in terms of similar versatility and variety, good stuff. If I ended up with a J bass that needed a pickup swap, I’d be curious about the EMG JCS set, but have no experience with them.