[Brightcolours]

Stupid quotation system. "Not always very useful" was quoting yourself, and it was the second question. The first one you asked was why the price was higher than comparable Canon EF-S and EF-M options, and then you said  the Fuji has a bigger focal range than both and is constant f4 which is a part of explanation. Not to mention the better build quality of the Fuji vs. the EF-S.

 

The Tokina does not play exactly well with APS-H sensors, it only starts working without heavy vignetting almost halfway through the range -- I tried.

 

Re: the shallow DOF... it's not be all end all of photography. A lot of the times... quite the opposite. That's not something I would really want in an ultrawide anyways - maybe there are some very specific usage cases, I can't think of any that would benefit me in my work. You could probably get what you want anyways by focusing close.

A higher price is reasonable, I question the amount of higher-ness. The FF Canon L is in the same ballpark, which makes the Fuji price look even more excessive. 

I know the Tokina can't be used at 12mm on the 1D APS-H, but it can well be used with it and give a similar wide FOV as it gave with your APS-C camera (at about 15mm)  (and also can be used on FF at about 18mm). That was my point... 

 

Why is constant f4 with an UWA a big plus for you, what constant f5.6 won't give?