#1
Looking at my little wall of cabs I figured I'd so a shoot out. The mic was positioned in between the cone and the cap for each.

Chain -
Ibby Series with a SD JB in the bridge
Misha style OD pedal
Decimator
Randall RM100 with a Ultra-Lead style module.
Cabs:
Bogner w/ V30s
Mesa w/ V30s
H&K w/ V30s
Peavey w/ K100s

First part of the clip is a mix test. Second part is just the guitars with processing turned off. The mix has just high pass and low pass filters on the guitars.

Mesa
https://dl.dropboxusercontent.com/u/3602793/Mesa%20Cab.mp3
H&K
https://dl.dropboxusercontent.com/u/3602793/H%26K%20Cab.mp3
Bogner
https://dl.dropboxusercontent.com/u/3602793/Bogner%20Cab.mp3
Peavey
https://dl.dropboxusercontent.com/u/3602793/Peavey.mp3



If you guys want me to host this somewhere else let me know. Those K100s are FAT.
Guitars:
Ibanez UV777P
Ibanez RGD2127FX
Ibanez RG3120TW
Ibanez RGD7421
Ibanez SA160
Amps:
Baron Custom Amps K88
Randall RM100
Madison Divinity II
Cabs:
Mesa 4x12
Bogner 4x12
H&K 4x12
#2
Just so we're clear, close miking individual speakers eliminates 95% of anything connected with "cabinets." You're listening to differences in mike location and in the condition of the individual speaker being miked. There's not a lot of useful information being generated.
#3
Actual cab dimensions and construction do change sound so the speakers are under a different amount of pressure in each cab. That said, even the speakers are different from cab to cab. English V30s in Mesa, Chinese in H&K and Bogner and K100s in Peavey.
Guitars:
Ibanez UV777P
Ibanez RGD2127FX
Ibanez RG3120TW
Ibanez RGD7421
Ibanez SA160
Amps:
Baron Custom Amps K88
Randall RM100
Madison Divinity II
Cabs:
Mesa 4x12
Bogner 4x12
H&K 4x12