Just a reply to say that I am glad this mini-review is useful to people - I had the same problem, not finding any concrete information / examples of this lens anywhere, so I thought I'd share some of my experience. I just hope this doesn't contribute to price inflation of this lens! (sometimes obscurity is good for second-hand values :-)
The 140 Macro does not replace something like the 150 SF, or even an old non-C 127mm f/3.8. Both these lenses have a soft, atmospheric look with shallow DOF wide open, much more like an old twin-lens reflex (which is a very nice look indeed).
The 140 Macro is an über-corrected, perfect flat-fielded lens which yields a different look suitable for critical subjects. I have not seen any typical optical flaw exhibited in any of my prints or scans.
Note: The images I posted earlier are directly linked to my DeviantArt.com account, I hope the URLs are stable so tat they stay visible. I plan to get a subscription here at APUG soon though.