I´ve bought this lens second hand from ebay in november 2012 and it´s been attached to my M6 since then. i switched from nikon to leica in the beginning of 2012 and journey to find best 28mm lens began. my first lens was VC nokton 35/1.4, whis is really good lens, also very small one, but 28mm framelines on my M6 reminded me that i lust for this focal length i used on my nikon FM2.
after few months of searching and looking around the internet, i found the one, VC color skopar 28/3.5. it´s tiny and solid lens with classic M39 mount with full rangefinder coupling down to 0.7 meters (2.5ft). despite the size, it´s 7 elements in 5 groups design. front element has convex surface like the one on some aspherical lenses (this one is not asperical, though).
so, while studying on scottish university for one semester, i finally found one, fortunetely located in england and won the auction (needless to say, i was ecstatic – it´s not so easy to find one nowadays)
you have to buy an adapter in order to use this lens on leica M cameras. i bought cheap one from china which was not very good, focusing was correct but i was furious about not being able to screw the lens to the correct position with white dot on the top facing upwards. so i decided to invest some money and bought original voigtlander adapter (roughly 40 euros), it´s very well built and lets me mount the lens properly.
focusing is very smooth, i think it can be comparable to real leica lenses. it´s made from brass, so it´s surprisingly heavy for its size. focusing lever is very easy to use and i can say it suits me better than the leica one.
note that it´s very slow lens and in order to take photographs in poorly lit environment you need to use either very fast film or just buy another lens with larger aperture (i use my 35 nokton). the problem is, if you load film faster than 400ASA and you shoot with film M on a bright sunny day, you are limited by it´s fastest shutter speed of 1/1000 s. that´s the reason i´m trying to get hold of ND filter with 39mm thread.
this lens is simply super sharp and very easy to use, i strongly recommend use of protective UV filter, it prevents dust from getting inside the lens and makes the front airtight and holds the slip-on lenscap better.
i´m no test geek, i use my lenses and this one is hell of a performer. i can´t think of situation where it let me down somehow. i use it in backlight situations and never had significant problems with reflections. most times i just set my aperture to f/8, focus at 3m and i´m ready to go. focus throw is very short and lets me change the distance quite fast.
in conclusion, this lens makes my M6 almost pocketable camera with perfect optical quality. you can check some of the photographs here on my tumblr or in this blog post.