Yes, the Quatro is the best 'bang for the buck' speaker, not only in the Vandy line up, but in regards to all the speakers out there.
A pair of Treo's with Sub 3's will get you to a Quatro. -Maybe even better, as you can position the Sub 3's to optimize bass output, though the graphic equalizer should minimize this.
I, too, am drawn to the MBL's like a moth to a flame. I am still waiting to find a pair of 121's at the right price. However, John Rutan told me that they don't scale well, and you might find out that the piano is way over sized in imaging.
For me, I just love the design, as well as the omni-directional concept.
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