@esch,
I concur with your opinon regarding the Zu vs. Maggie.
I, too, tried a pair of Zu Union, and Omen speakers. In both cases, they were very close to my Vandy speakers (Treo's and VLR's), but seemed to lack the 'refinement' Vandy offers. I suspect the same occurs with Maggies.
Re Bass:
One thought that occurs to me is that the Schiit Vidar Monoblocks aren't up to the task of powering Maggies. Yes, they work, but I think you would be surprised if you put in a nice Class A amp, Heck, even an AB amp like McCormack should probably tighten up that bass. Schiit makes an impressive product for the money, but Maggies really like a good power source to deliver the goods.
My 2 cents...
Bob