[Brightcolours]

So, we now expect a Tokina to be the same price as a stop faster and much more glass containing Sigma Art lens? Or be more expensive than a faster Nikkor?

[Klaus]

The Tokina is half the weight and length of the Sigma lens ...
As much as I like Sigma lenses these days - regarding its "extension tube" it's quite pathetic really.

My point was: an unjustified price for a 3rd party lens in today's pricing landscape.

And about the size and weight... Of course it is, that is the norm anyway with lenses that are a stop faster

And on the tube... It is not an extension tube (lens does not focus closer), but rather a mirrorbox-replacement-sans-mirror, or integrated adapter.

Make a guess why I put the "extension tube" in quotation marks ... ;-)

[Rover]

So, we now expect a Tokina to be the same price as a stop faster and much more glass containing Sigma Art lens? Or be more expensive than a faster Nikkor?

If you're surprised about the surprisingly way too bold pricing, don't be: after all, many manufacturers thrive on this kind of thing... sometimes crossing the border way into the realm of daftness.

Tokina, after all, is at least a competent manufacturer, and their example is a rather benign one. Besides, both the Nikkor and the Sigma come with some inherent caveats, the lack of which may be a value adding proposition for many.

[borisbg]

Did Tokina use the same optical design as the MF version of the lens? Lenstip shows that resolution is good, but vignetting is quite high.

[Brightcolours]

Did Tokina use the same optical design as the MF version of the lens? 

Yes.