Man, that's a good question, and one which plagues us all, constantly. I'll apologize in advance for getting long-winded.
If you were to say, in a general sense, that lower-wind/output humbucker offers certain tonal characteristics that a high-output pickup doesn't deliver, there's one dilemma.
Consider Ace Frehley ca. '74. Les Paul into a Marshall with only a cable between the two. What's going to get you the best uumph and grind? A dimarzio super distortion. Will that give you the best bluesy sound? no. Will it give you the quintessential KISS sound? Damn right.
Consider a Brad Gillis/Warren DiMartini type of guy in the early 80's. Amps aren't a world away from the 70's vibe, but a little grittier. Pedals are becoming more prevalent, but power-rock still needs powerful pickups. Hence the JB/Duncan distortion or a Dimarzio Super distortion being preferable to a PAF style output.
Now consider Vito Bratta from White Lion. I think he used a strat with a duncan 59 in the bridge. I'm not saying he had the most aggressive tones, but he had GREAT tones on Pride. he also was using higher gain amps/effects, so he didn't need the souped-up humbucker that was necessary a decade prior.
Basically, it's a balancing act of who is doing the work for your gain: your pickup or your rig? Nowadays we have the option of both. So if you're Dave Murray in '81, you really need a Super Distortion to get the most aggressive sound. If you're Slash in '90, with a high-gain amp (for the time) a Duncan Alnico II Pro does just fine. Today, with the availability of cheap pedals, multi-effects, and modeling technology, I personally think that a highoutput pickup is less important. But I still use them for the sheer girth of sound that they have (I'm fortunate enough to have a number of guitars).
So having said all that, a set of Seth Lovers will sound KILLER no matter what; unbelievable pickup. But, if you're plugging a seth lover straight into a tube amp with no pedals and turning everything up to eleven to get a high-gain sound... that's not the best setup. A JB/Duncan Distortion/DiMarzio Super would be better.
If you have a few pedals and a good rig, a moderate pickup like a 59, PAF Pro, or a Screamin' Demon would suit you well, and still be able to "tone down" and do a great mellow sound.
If you're happy enough with the JB but want a mellower vibe, I like the 59/Custom Hybrid and a 59 neck (or the jazz neck you have would be pretty similar). I think you'd find it a refreshing change of pace from the JB. Or even a straight up 59 bridge model. And when you need to juice up the gain via a pedal or a high-gain amp (or modeler) it'll deliver the goods if you can play that aggressively. me personally, if I were to transport myself through space and time and play through Fast Eddie's rig - i couldn't play "ace of spades" convincingly to save my life.
