So in the other recent pickup thread I posted (trolled ?) my dislike for the JB, which seems to get a lot of love. Honestly, I've heard guitars with JBs sound really good, just not amazing. The warmth that a lot of people like about them sounds like mush to me (don't want to start a debate about that, just setting up my questions...).
I think it comes down to the magnet. All my 6ers have EMG 81s in them, and I am generally happy with them, other than the slight "plastic" sheen to the upper mids. I really like the Duncan Distortion and Custom as well, which are both ceramics, but I've never tried them in my guitars. I am thinking about putting a passive in one of my 6ers, and I am debating which one...
So, my questions are...
1 - what are the differences in the general tone between an alnico and a ceramic pickup. Say, you put the different magnet in the same pickup, what would the differences be?
2 - what are some other ceramics to investigate besides the distortion, custom, miricle man and painkiller?
I think your first question might be oversimplifying a bit. I still remember a massive Guitar Player pickup shootout from the early nineties, where Seymour Duncan said that the differences between ceramic and alnico were greatly exaggerated, and that you have to understand the differences between them when you are designing a pickup.
Having said that, Duncan is the greatest purveyor of one design, multiple pickups of anyone out there. The Distortion is ceramic, and the JB is alnico 5, but everything else is the same. The Custom is ceramic, the Custom 5 is alnico 5, and the Custom Custom is alnico 2.
So, having said that, I've noticed that as you go cycle through alnico 2, 5, 8, and ceramic, the lows tighten up and the uppper mids become more pronounced. However, with modern high gain amps, there really is no longer a need for a super hot pickup to get the amount of distortion you are looking for. It is a far better idea to find the pickup with the tonal response you are looking for, since you're just going to raise it as close to the strings as you can before it starts to over-compress.
I think your problem with the JB is the modern version of it, although I don't want to hazard a guess, since I know you've been around long enough to have played the originals. The modern JB is 16.4K, while the "vintage" spec is closer to 12.5K. Ever since I got my Wolfetone JB7 rewind, the stock sounds brittle up top, and muddy on the bottom to me. They definitely suffer from being overwound in the race to high output.
I think your problem is similar to mine: the big guys aren't mass producing anything that really suits your needs, which makes perfect sense, since they weren't mass producing any guitars that suited your needs, either. However, considering that you have EMGs in your sevens, I'd start with a set of Duncan Blackouts first, since I think they are a great middle ground between the somewhat cold EMG, and the mush you don't want to live with. I know you are mainly playing sixes these days, but the quick connects make it a fast swap, and if you like them, then there is no messing with the complete electronics replacement in your sixes.
If I had to pick a passive for you, it would be the Lungren, hands down. It has that EMG-like searing top end, but without that artificial midrange.