new Metabones adapter gives nex crop factor higher-quality full frame look.

What strikes me as odd is the current mount selection. EF with electronic contacts (insane at $599), Leica R without (better but still way expensive at $399), and Alpa ($449)? I didn't even know there was a 35mm Alpa mount. The wisest thing in my opinion would be an Alpha mount without the expensive electronic guts, which you could then easily adapt to Canon EF (obviously without aperture control and AF), Nikon F, Pentax K, Contax C/Y, M42, Leica R, etc.

Though perhaps that nifty element they've got in there has to be at a precise distance from the lens and therefore would mess up IQ if you popped another adapter on?