I don't know if this will help you, but at the moment, my rig is
a Vetta 2x12 combo with an external 2x12 cabinet. One of the cool things about the Vetta is that it has discreet amp models in stereo - in other words, I can have a Marshal Plexi in the Vetta's speakers, and a Dual Rectifier coming out of the Extension cab - there is an algorithm in the Vetta that sets a slight delay and slight pitch increase (like 9 or 10 cents) to off-set the two cabinets, so the sound is really full, almost like two separate guitarists playing. It really is cool. I also use a sub, but that will get complicated explaining it.
I love this set up. It's loud, compact and very big sounding. It replaced a touring rig that consisted of two dual 15 cabinets powered by a stereo 400-watt power amp and a custom pre-amp, and then a huge rack full of stuff. I tour moderately and lugging that stuff around was insane. I get better sounds with the Vetta (and if I never said anything - nobody could tell the differnce on my album that I used
a Vetta instead of a Marshall)
Anyway - playing in stereo is great for me, and I think it's great in general, especialy if you play in a trio as I do - it fills up a lot of space.
I hope you have some better understanding of stereo and guitar. But I must confess too, that NOTHING beats a Fender Strat or a smokin' Les Paul SG into an old Marshall 1968 Plexi on 10 - or any other nice axe into a great amp like a Bogner or a Boogie and just wailing - nothing!
Best of luck..