I took delivery of an Auto-Takumar 55/2 today from Japan (I'm in the UK) which amazingly arrived in less than a week. Very impressed with how small it is - it's significantly smaller and lighter than my Super-Takumar 55/2, itself no heavyweight - the Auto-Tak has a 46mm thread like its even smaller sibling the Auto-Takumar 35/3.5 I also recently acquired.
Focusing is lovely and smooth (a major appeal of the Taks for me) and the aperture clicks are very good too, though less dampened and more tinny and clicky sounding than my Super and S-M-C Taks. I like that the aperture ring is right near the end, like a preset lens almost, as this makes it easier to access on my digital bodies, and the aperture scale is more clear to see being farther from the camera body and overhanging flash.
Only had a quick play in the garden but very happy so far. Colours seem very natural and real, it has an interesting character wide open, and smooth bokeh highlights as you close down, helped by 10 aperture blades. In due course I'll do some head to head shooting with the Super-Takumar 55/2, though I'll likely keep both as they're quite different in handling, the Super focuses closer, the Auto has those 10 blades not six, so they're far from similar versions of the same lens. Very impressive for a lens that's almost 60 years old.
A shot wide open with my Samsung GX-1S.