I've just spotted the latest in a long line of posts, dismissing the 135mm focal length for being too long, too short, uncomfortable, useless or obsolete.
That may be true for some, but I have the opposite view; It is a very handy focal length if used to showcase it's strengths.
Let's face it, in APS-C terms, we're talking about a 200mm f/2.8 (usually). A classic focal length with a fast max aperture.
My version is a Pentax A 135mm f/2.8. If Pentax chooses to design a modern DA or Ltd. version, I'll happily buy one.
Rather than try to convince anyone with descriptions of what this FL can do, here's a small sample. Check out the !.Q., skin tones, Bokeh and rendition.
Ron