Mike's are reverse engineered from a pair in a in a '63 that was a very good sounding bass, he's personally owned at least 10 vintage Thunderbirds and favored this particular pair as a starting point, they are wound to two different specs 8K neck 9K bridge. Construction wise they are exactly like the original Gibson pickups (metals, wire etc.) that he had to work with. His covers are stamped by the same company that did the originals for Gibson, and can be finished in chrome, nickel or black as examples on his website show. At the time they were being developed and for some time after Mike requested that I not say who produced them for him but as of this point I'm free to say that TV Jones did all the production initially, he was not able to keep up with demand tho, so now Seymour Duncan makes them as well. Mike also sells the surrounding rings as a separate item. Interestingly Mike originally wanted Jason Lollar to produce them, but at the time he declined as he felt there wasn't enough of a market.
I currently use them in 4 of my basses, two BaCH's, my Gibson Nikki Sixx Mk.II (rewired to '63 spec) and, of course in my single pickup Lull I'm very impressed with them and am an endorsing artist for them as listed on his website, I do not ask for, or get any compensation or discount for that tho, it's because I like them. Other more famous users include Tom Petersson, Stu Cook, Bryan Beller, Jeff Ament and Hugh McDonald.
Mike's do cost more, he runs a legitimate business with a storefront and pays a small number of employees a living wage making both new instuments and repairing others. perhaps that's why.
You can hear mine live on quite a few of my band's vidoes, I'm happy to send anyone interested a few Youtube links.