I thought they were good, so I couldn't call it ho hum. IMO, it was for the most part, a very clean performance (maybe other than the colgada). Maybe some day, I'll be able to dance as well as them.
However, in principle I do see your point. At times, it lacks what I would describe as "attitude" (just what you wanted, another nebulous term). Some of this may simply be due to their interpretation of the song. I looked, but didn't find any other videos with them, thus I couldn't test my hypothesis.
Now it's difficult for me to give an objective comparison of the two performances because:
1) Canaro's "Milonga Criolla" is one of my favorite milongas (along with Canaro's "Silueta Portena").
2) The style of the songs dictates a very different interpretation.
In any case, I agree that the second couple had "it".
FWIW, for me, the way to evaluate/compare cadencia, is to watch how dancers walk (not so much when doing figures).