[davidmanze]

It's easy to buy a cheaper 2nd hand 90 or 100 macro. Is there really a market for that new lens?

Exactly, my Sigma 105mm 2.8 is a great lens, sharp,sharp,sharp, I bought it S/H for 220 euros.

 

Well, AF isn't THAT useful at macro distances.

 

It depends what your shooting, if it's flying critters AF is sometimes the difference between getting the shot and your subject having buzzed off!

 

A tuff call finding customers here,

 

            The "macro juggling syndrome" is for small apertures for DOF, high shutter speed to freeze the action and hand shake, lowest ISO to keep down noise, most macro is done at small apertures, so sharpness is often limited by refraction.

 

      The Samyang is big, not cheap, no AF, no stabilization, manual from the body except Nikon (and maybe Pentax) and it's up against top flight competition from all sides many of which are on the S/H market for half that money. 

 

  A few macro shooters will  still be operating within the remaining parameters but as automations can be switched off anyway, I see no advantage committing oneself to all manual!