That video didn't sound the greatest but, it seemed like the pair of 1x12's had more of a tight low mid punch and was overall all more defined than the 2x12.
+1 Their summary didn't really match what I was hearing. The additional low end push of the 212 resulted in the 112's sounding just a bit more mid defined to me, which is what you would expect when comparing a 212 and a 2 x 112 of similar design. Anyway, both sounded great, and very similar. This is also how another TBer described them when he did a direct A/B. Again, close enough, and slight EQ would most likely make them even more similar.
Jim did a nice voicing job, resulting in what seems like very little downside (other than cost) to allow for a modular rig that performs similarly to the larger cab. Nice!