Getting there -- NEX-5 & Kowa (EIKI) 50mm f1.2 Projection Lens.
The Kowa Super Prominar-16 50mm f1.2 projection lens is so far the fastest of the projection lenses I have, beats out the Paillard-Bolex 50mm f1.3 by a hair. It's also the only projection lens so far that won't focus to infinity with my home-brew focusing helicoid. The end of the lens almost touches the helicoid, and still not enough to focus more than a few meters away.
Unlike the razor-sharp Paillard-Bolex 50/1.3, this one is much softer. I have only used it once today, so haven't really gotten a feel for it yet, but I kind of like how the pictures come out of the lens.