I shall tell you a tale.
When I got my IIIc a couple of years ago, it came with a 3.5cm Elmar and no external viewfinder. I used it this way for a couple of rolls. The lens was "tired" and in time I replaced it with a 3.5 Summaron that was in far better condition. About 6 months ago I bought another Elmar, from Aperture in London. This one is clean, clear and well-sorted. It now lives with a 9cm Elmar in my IID "carry-kit" as below:
IID kit.jpg
In comparison, this is a TINY lens. It is no bigger on the camera than a collapsed 5cm Elmar. This picture shows it alongside my Summaron and a 50mm Colour-Skopar:
P1000081.jpg
In terms of handling, it is quick and positive to focus. It requires an external viewfinder, it is true (in the top picture, the small black case on the top row is the Helios one) and the aperture is set, like the 5cm, with your thumbnail, but that is a small price to pay for compact size and more than passable results.
Ah yes, results. Bear in mind I use this lens stopped down, since I use it outdoors with ISO400 film, so most exposures are in the f6.3 - f9 area, but I am happy with what I get. Here is a recent example:
If you follow this link:
http://farm4.static.flickr.com/3010/...9b0a7d39e2.jpg
You can see a big version of the same shot. You can see the snowflakes, and the texture of the church walls.
I have other 35s, most notably the 2.5 Colour-Skopar Pancake I which is a sharp and stellar performer by any standards, but sometimes it isn't about perfection. Sometimes it's about the joy of using something jewel-like and well made that turns in a pleasing performance in spite of being (just) old enough to be my grandfather.
Regards,
Bill