I played a Halloween gig last night switching off between an NC112 and an MG12T-V, and I also tried them both stacked together since they were there (sorry, forgot to take pics, I was too busy looking at all the wild costumes in the crowd). I like both cabs. As others have described, the NC112 is warmer and smoother in the mids while the mids in the MG12T-V are more prominent and can get a bit aggressive if you want them to. I believe the MG probably goes lower, but the NC sounds like it has stronger lows since it has the smooth low mid warmth to complement the lows. Both have a small footprint and are easy to carry (although I can definitely feel the weight difference with the NC112's extra few pounds). They also sound good together even though they have different design goals, although when I played both in the last set the band and the crowd were pretty loud so I'll have to try that combo again when I can hear them better.
I wouldn't call the NC112 old school, since it is much clearer and with a more extended range than what I remember as old school, but it's definitely smooth and warm.
I'm definitely a fan of modular rigs, and not sure at this point if I like the NC or the MG better, but either is a winner for me.
Bob