Hi all and thanks to all who have responded to my query. Much appreciated!
@wilco23: I agree with you - if you pay that much for a lens, it better be (near) perfect. I know there is no such thing as perfection, since lens design is all about trade-offs. However and FWIW, even my 'lowly' Tele-Tessar 85/4 ZM has much more optimally shaped aperture blades.
As I stated in my previous post, my intended use of the A-E 180/2.8 is with the D800E. With such a high-res sensor, diffraction becomes noticeable at f/5.6 to f/8. Therefore, it is important to me that the lens is 'well behaved' at all apertures from wide open to f/11. Unfortunately, this seems to be the range where the ninja star issue on the A-E 180/2.8 is at its worst.
@Almass: you said "The 180/2.8 APO VII shows Ninja, albeit to a lesser extent that VI". Does this mean that you have a VII-version (P/N 11357, S/N ≥ 4000000)? If so, could you post images of what the aperture looks like @ f/4 and f/5.6?
Also, you said "I would not use a long Tele for backlit or front lit Macro shots anyway. I would use the 100/2.8 Macro on a tripod". I agree regarding macro - that's what I use my Makro-Planar 100/2 and 50/2 for. However, with nature photography, you often can't get close enough to the subject (still wishing for a magic carpet). Experience shows that I would use the APO-ELMARIT primarily near its close-focus limit, and shallow DOF (combined with pleasing bokeh) is one of the main reasons for me to use an 180mm f/2.8 lens in the first place.
TIA to all of you for any replies!
Ron