[toni-a]

The Laowa is f/2.8 - and with 5 stops of vignetting, as Klaus has demonstrated. Not in the same ballpark for hardcore astro I would say (though it looks fantastic for landscape and cityscape shooting stopped down to f/5.6 or thereabouts... which is a different use case).

Well, maybe not in the same ballpark as hardcore astro, but it's still a fish-eye nonetheless, many get bored with the inevitable distortion that makes most images look more about fisheye than anything else ....

   As you say it's real strong point is keeping the verticals vertical for cityscapes and the like, to me that makes for better photos in the real world ....... and for nearly a third of the price .....

Well said Dave, a fisheye is a wonderful and must have lens, but i the end all the photos will end up looking the same...I always carry a fisheye with me, and always the fisheye pictures are highly regarded.
For events and gatherings fisheye pictures are often chosen as the cover photo and here the magic ends... usually per shooting event you need maximum 2-3 fisheye shots no more but they are usually absolute keepers.
That's why I always carry a cheap 8mm fisheye mounted on Sony A6000 or 7D2 I take  2-3 shots with it usually upon arrival, then it goes back inside the back till the next event...
So to make it short: is a fisheye needed: absolutely however you will take only 2-3 shots with it that will be highly regarded

[Rover]

Then the 14/1.4 will take the cake.