#1
How would running a 4x12 Marshall 1960a with Celestion G12-75s and a Vader 2x12 with Eminence Legends sound in stereo? :x
Baron K2 SE 120
MILLS 4x12 Afterburner
Eventide TimeFactor Delays
ISP Pro Rack G Noise Suppressor
BKP Warpig pickups
#2
They might not balance out perfectly, but it's worth a shot.
Alvarez dreadnought
Gibson SG
EC-1000
Homemade Strat (seymour duncan classic stack p/ups)
Vox Tonelab (original desktop model) with full board footswitch
Vox AD50
Avatar V30 4x12 cab
#3
only one way to find out..

plug em in
My Guitars:
Gibson Les Paul Studio
Epiphone AJ
Ibanez Strat Copy

Amps:
Orange Tiny Terror Head
Old beaten up Peavey cab
Marshall MG30DFX
#4
I haven't bought the 2x12 yet, so I cant :p

My main concern is 4x12 with 2x12 in general
Baron K2 SE 120
MILLS 4x12 Afterburner
Eventide TimeFactor Delays
ISP Pro Rack G Noise Suppressor
BKP Warpig pickups
#5
Should balance out fine. The vader might be louder than the Marshall because of it's tighter projection. Personally, when running cabs in stereo I have the cabs side by side, but they are turned away from each other very slightly. I just prefer it to having it at one side of the stage to another. Sometimes leads sound sloppier through one cab, helps to mush them together a bit.

..yeah, i'm a noob.
Major of 7 String Legion 7 > 6

Carvin DC747
Ibanez RG2228
Schecter Avenger Custom Shop
and my baby....
Gibson Explorer Studio