I've had recently the opportunity of trying a Canon LTM 35/2 in an antique camera shop in Buenos Aires. It impressed me. ergonomics are fantastic, really tiny, and I took a few shots inside the shop and some outside. Bokeh is really nice and the lens is quite sharp. The only reason I didn't brought home was the $600 price tag, a bit higher than its market price on the 'developed' countries (on south america imports have a high tax, so local prices tend to be higher).
In this trip I got krosya's 35mm Ultron modified to focus down to .7m, and it's a superb lens. I have using it a lot on the R-D1 and am impressed with how it draws. Beautiful, smooth out of focus rendering and sharp wide open. Also, no flaring so far (and I'm not using the hood). It's really a gem!
I also ended up getting a 35mm Summicron v4, but I bought it online and it didn't come with nor rear nor front caps, so I ended up not using it on the trip to not risk messing up with the glass. In NYC I got the caps and used it on the M4, great lens. Still to use it more on the R-D1, but from a previous opportunity with a friend's v4 I can say it's a tad wider than the Voigtlanders, and bokeh is smoother. But not much smoother than the 35/1.7's, it feels quite close. Haven't used it enough so far to talk about how it draws versus other CV 35s, still starting to use it. But it has a much, much smoother out of focus rendering than the 35/1.4, with less flaring, wider fov, and about same size. But 1 stop slower.