Pickup Advice from an Engineer's perspective?

The 85 and the 89 are the same pickup, just the 89 has coil-splitting capability. Maybe they have some other differences (like how the 6505 and 6505+ or 2-channel and 3-channel Rectifiers sound different even though they're supposed to be the same), but I've not heard of them. And I really hated the 85 in the neck of my RG, which is the brightest guitar I've ever played (5-piece maple/walnut neck-thru body & core with mahogany wings) - sounded too woofy/tubby/wooly, and if it had that sound in that guitar, I can't imagine it being any better in a darker one! So for you, Ghost, I'd definitely say 81 Bridge/81 neck (which is what I have in my EC-400), but I've also heard good things about the 60 in the neck, though not tried it myself.

Does the 89 actually sound like an 85 when in humbucking mode? If so, I might be interested. I love how the 85 sounds in the neck. From what I've read the 89 as a humbucker is supposed to sound like an 85, but doesn't really...
 
What does coil tapping mean?

A coil tap is essentially a 'shortener' that can be turned on and off. Suppose you have a coil, and somewhere in that coil there's a little conductive bit exposed that's wired up to a switch that'll either not connect it anywhere or connect it where the 'proper' end of the coil should be - when the switch is not engaged, the coil operates normally, and when the switch is engaged the coil is effectively shorter because you've given it a new endpoint.

Some argue that coil splitting is a type of coil tapping, as you're 'grounding' one of the coils, but that is weak because the two coils are independent and humbucking is a combination of two coils, not a single coil of its own.

Jeff
 
Rather than trying to address any of your specific points, or point out the logical futility of a statement like "all the top guys use the 81," all I'm gonna say is: don't knock it 'til you try it. The 85 is an Alnico pickup while the 81 is ceramic/alnico, so think of it as, say, a JB vs. a Duncan Custom. To me, I prefer a fuller sound for the bridge pup and a more cutting sound for the neck, so reversing the "classic" (uggghh) Zakk Wylde set makes more sense and sounds better to me in my bright Ibanez RG (but not in my all-mahogany EC-400), simple as that.

I hear ya.
 
I know Killswitch Engage Use 85' in the Bridge, Their Guitar tone pwns Live and Recorded.

Exactly what is the sound difference between 81's and 85's?
 
I know Killswitch Engage Use 85' in the Bridge, Their Guitar tone pwns Live and Recorded.

Exactly what is the sound difference between 81's and 85's?

The 85 has higher output, and larger frequency response:

http://www.emginc.com/specindex.html#81

From the EMG site: Although the EMG-85 has more measurable output than the 81, its frequency response and string interface are different. The 85 uses two Alnico magnet loaded coils with a wide aperture to maintain a beefy lowend and a fatter top end.

I don't use 81s anymore for anything, I think the 85 is a better pickup in every way, for any style of music.
 
The 85 has higher output, and larger frequency response:

http://www.emginc.com/specindex.html#81

From the EMG site: Although the EMG-85 has more measurable output than the 81, its frequency response and string interface are different. The 85 uses two Alnico magnet loaded coils with a wide aperture to maintain a beefy lowend and a fatter top end.

I don't use 81s anymore for anything, I think the 85 is a better pickup in every way, for any style of music.

Everyone says that, but in real world situation the 85 doesn't produce as much output in the bridge as the 81.

The thing keeping me from trying an 85 in the bridge is that it's supposed to have a lot less treble and a lot more bass... which is the complete opposite of what I'd want when tuning down low...