I did a little blurb on the different Gibson humbucker models on my website. It's not new info, and is only slightly rewritten from all the Gibson gab, but it's a handy, quick comparison... It may help you.
Gibson Humbuckers, In A Nutshell
Paraphrased and edited from the Gibson website…
The sound produced by the early Gibson “PAF” humbuckers was caused, in part, by inconsistencies in winding the bobbins - a result of the lack of automatic shutoffs on Gibson's winding machines in the late 1950s. Seth Lover, who invented the humbucker, always said they wound the bobbins "until they were full," and original examples suggest that employees stopped the winding machines after the counter reached approximately 5000 turns.
When the two coils in a pickup have a different number of turns, that variation puts a little "edge" or "bite" on the sound, replicated by the Burstbucker models. Gibson carries the Burstbucker replication process two steps farther, with unpolished Alnico II magnets and no wax-potting of the coils, just like the originals.
The later “patent number” pickups with machine-determined equal coil windings produced the "creamy" sound that Gibson's '57 Classics and others replicate.
BurstBucker™ pickups from Gibson Gear now give guitarists a choice of three replica sounds from Gibson's original "Patent Applied For" pickups - the pickups that give the '59 Les Paul Standard its legendary sound. The three BurstBuckers™ - all with unpolished magnets and non-potted coils, like the originals - represent the variations found among vintage Gibson humbuckers. Gibson USA put the first BurstBuckers™ on a production model with the Gary Moore Signature Les Paul in the Summer of 2000, and Gibson's Custom division then equipped the Class 5 Les Paul, Custom Authentic '68 Les Paul Custom and Custom Authentic '58 Les Paul Standard models with BurstBuckers™.
Burstbuckers are available with German silver nickel-plated covers and are offered in three different versions:
The IM57A-NH is slightly underwound, with medium "vintage" output, and works well in both bridge and neck positions.
The IM57B-NH is wound in the range of Gibson's '57 Classic, with slightly hotter "vintage" output than the BurstBucker-1, and works well in the bridge position with a BurstBucker-1 in the neck position.
The IM57C-NH is slightly overwound, with hotter output, and works well in the bridge position with a BurstBucker-2 in the neck position.
The BurstBucker Pro™ enhances the vintage "edge" of Gibson's popular BurstBucker™ pickups with the added feature of an Alnico 5 magnet. Gibson developed an Alnico 5 BurstBucker™ specifically for new Les Paul Standards. The outstanding performance of this new pickup (originally called the BurstBucker V) led to an overwhelming demand for an after-market version. With the BurstBucker Pro™, all "Pure Tone Lovers" can now have stunning humbucking tone.
BurstBucker Pro™ humbuckers are offered in a calibrated pair; the neck position (IM59A), and the bridge position (IM59B). Output of these pickups is similar to the standard BurstBucker-1 and -2 model. And BurstBucker Pro™ pickups are wax potted so that they can withstand loud volume pressures without annoying feedback. Each model is available with either German Nickel Silver- or 24ct Gold-plated covers.
'57 Classic Humbucker
With its "Patent Applied For" decal on the baseplate, the '57 Classic and '57 Classic Plus are faithful replicas of the famous Gibson humbuckers that helped define the music of the late 1950s. The '57 Classic features Gibson's special Alnico II magnet, vintage enamel coated wire, nickel plated pole pieces, nickel slugs, maple spacers and vintage-style, two-conductor, braided wiring. The '57 Classic is available with genuine gold-plated covers, nickel-plated covers, or open coils.
'57 Classic Plus
The perfect bridge-position companion to the '57 Classic, the '57 Classic Plus mimics those late-1950s humbuckers that received a few extra turns of wire. This treatment gave the pickup slighter higher output without sacrificing its rich, vintage tone. It helps overdrive tube preamps to a smooth level of saturation without becoming overpowering. Made with the same features as the '57 Classic, the '57 Classic Plus is available with genuine gold-plated covers, nickel-plated covers, or open coils.
490R, 490T, & 498T
These "modern classic" pickups feature tonal characteristics similar to the '57 Classic, but deliver a slight increase in the upper mids, for a more contemporary humbucking sound. The special Alnico II magnet gives these beauties a singing quality that delivers on demand.
The 490R, with its neck-spaced pole pieces, is calibrated to match the bridge-spaced 490T for a perfect match.
Put a slightly hotter Alnico V magnet into a specially wound coil combination, and you get the 498T "Hot Alnico." With its higher output and emphasis on mid-ranges and highs, the 498T is the perfect rock bridge pickup.
Available with chrome, gold or nickel covers, or with open coils, the 490R, 490T and 498T are also available with four conductor shielded wiring for series/parallel/split coil variations. Factory-installed 490R, 490T and 498T pickups have two conductor wiring.
When you want a smokin' neck pickup with incredible sustain and cutting power, try the 496R "Hot Ceramic" neck pickup. You'll be amazed how the high-output ceramic magnet adds more highs with increased definition and no muddiness.
If it's no-holds-barred, in-your-face hard rock licks you want, look no further than the Gibson 500T for your bridge spot. The powerful multi-ceramic magnet structure enables this monster to cover lots of territory. It can scream or growl - never losing its rich combination of enhanced lows and crystal clear highs.
Available with double black or black/creme (zebra) open coils, the 496R and 500T are also available with four-conductor shielded wiring for series/parallel/split coil variations. Factory-installed 496R and 500T pickups have two-conductor wiring.
Gibson's Gear division offers the extreme-output Dirty Fingers™ bridge pickups as replacement units that will max out the attitude factor on any electric guitar. Once described in Gibson Guitar literature as "The critical union between power and dirt," the Dirty Fingers has returned after a 20-year silence on the Tom DeLonge Signature model. Because of its aggressive tone, Dirty Fingers pickups will also appeal to those who play tuned down nu-metal. The Dirty Fingers pickup comes with a four-conductor lead and is wax potted to eliminate unwanted microphonic feedback.
I have the 490R/489T combo in an LP Studio I redid a few years ago, and find them much to my liking - very classic Gibson Les Paul tone, no surprises. A LOT of Gibson models (LP, SG, ES) used to come with this combo, before Burstbuckers hit the scene.
The 496R/500T (ceramic) pups that came stock in my Flying V were loud, brassy, and just too harsh for me - I swapped them out within a few months.
I haven't played any of the Burstbuckers.