Re: What's the verdict of humbucker aficionados on the Burstbucker Pro?
One thing I would like to add to this is that aftermarket BBs come potted no matter what wind strength or magnet they have, but BB 1,2, and 3s that come stock on guitars do not have potting.
I believe this is exactly backwards. The ones put in guitars were changed at some point (maybe 20 years ago or more) to being potted, but the ones sold aftermarket were not. The thought is that someone buying a Gibson guitar isn't necessarily looking for an unpotted pickup and all that comes with it, so that person might end up complaining about the squeals and filing a warranty claim. But someone who buys a BB pickup on the aftermarket almost certainly knows what they are getting into, and is doing so deliberately.
All BB Pros are potted. Also of note is that they came in #1 and #2 versions (but no #3 TMK). Another bit of trivia is that they were originally, and only briefly IIRC, called Burstbucker V's (as they were when I bought my new '04 LP that had them). They become potted BB 1's and BB 2's when you thrown an A2 in them...which, IMO, is the thing to do with them if you want "classic" Gibson humbucker tones.
As for tone: Aggressive and cutting, but not inherently "juicy aggressive" like your classic P.A.F. Big, stiff, clattery bottom end that can get overwhelming, biting top end, not a lot of midrange richness. Really good when that works for what you're doing, but definitely a more "modern" tone than a "classic" P.A.F. style. They work best adjusted higher, rather than lower, and played through amps with really good tone controls (graphic e.q. is the best for dealing with them – it can inject them with the mids they are lacking, and take down the aggressive, stiff low end on them).
FWIW, they pair great with Fender Single coils. IMO, they generally sound better there than they do in Gibsons.