I've read a few reviews on the HD which say it is what the Duncan JB *SHOULD* be. All of it's sonic strengths (drive, liquid leads, cuts easily through a mix), but none of it's weaknesses (sometimes icepick highs, sometimes flubby lows). Like I said before, I've used the JB for a long time and every time I've tried to use a different pickup, I just cannot quit the JB. I have generally been able to find all of the tones I've needed with the JB. If the HolyDiver has some of those sweet JB-like qualities, but with some extra icing on top, then maybe that's the one to start with.
The reason I was looking into the A-Bomb bridge, is the description says it sits in between vintage and modern. So, it's heavy enough for brootalz if that's what the need is, but it can clean up decent for more classic tones. By aggressive, are they more powerful? More treble? More grind?
Just "aggressive" - I think you have to hear it to understand 8)
I've had a JB (early 80s one) in my SG and replaced it with a ABomb. The JB had some qualities and I can understant why one may like it, but it was also lacking the dynamic, definition, note separation and articulation that are BKP's trademark and IMHO the main reason why you love or hate BKPs. To make a long story short: BKPs will respect your playing, for the better (yum) and worse (and yes, sometimes it hurts :mrgreen:).
The ABomb is a very different beast from the JB. wrt/ output level the ABomb is AFAICT not far from the JB but it at first seems quite a bit lower due to the aforementioned BKP specifities - this pup remains tight and articulate whatever amount of gain you use. Now the voicing is very different, the ABomb has incredibly tight lows, a throaty and very dense low-mids growl thing, full blast aggression in the upper mids (not spikey or harsh, but well... aggressive :mrgreen:), and clear highs. It's a real killer for heavy riff work, but while not lacking weight and body on leads it doesn't have the fluid/liquid thing of the JB and none of it's compression. It took me some time to get used to it, and it still shows any playing mistake so it's not as confortable as the JB or even the Crawler for lead work, but boy it sound huge and massive and yet cuts thru a dense mix like a hot knife thru butter.
Is it heavy enough for br00talz ? Well, I'm not into metal but "br00talz" is kind of an understatement as far as I'm concerned: this pup it takes no prisonner and makes no mercy, it kills, maims and slaughters :twisted:
And yes, while doing all of the above, it's not a one trick pony and also works surprisingly fine for more classic rock tones - with a twist - and even bluesy stuff when you roll down the volume. It of course retains a more modern voicing but is still very organic - thanks to the alnico magnet - and can get quite close to a (less bright and open) RiffRaff. It will obviously not sound just like a vintage PAF/Patent #, but despite the (justified) "90s metal" label it can really do much more and nails 70s hard-rock tones (AC/DC, early BÖC etc) - or at least it does in my SG.
Final disclaimer : I've only used this pup in my rather dark SG and I'm not sure how it would work nor if I'd like it in a brighter guitar, but you can check Sam Coulson's vidz on youtube, the guy as some nice tones from it in a LP.
I was also looking at the BlackDogs since one of the dudes from the band Godsized (whom I actually found out about because of the BKP site) uses them. The other guitarist uses the VHiis. I think I'm more accustomed to higher-output pickups, though, for their feel. I don't necessarily need all the power to push the preamp, but they usually feel more comfortable to play to me.
Most hi-output pups are very compressed, which can make them feel "more confortable". If that's what you hope to get from the higher output BKPs you may not find yourself at home, even the Crawler - possibly one of the most compressed BKPs - has way more dynamic than a JB.
My 2 cents...