Rokinon 12mm vs Zeiss Touit 12mm

[TreeofLifeStairs]

does anyone have any hands on experience with both of these lenses? It will be used on my NEX-7 to take pictures of my staircases (I build staircases for a living). I'd also like to use it for astro photography but that is second in priority to the staircases so I'd like it to be as sharp as possible with as little distortion as possible. Im not thrilled that the Rokinon doesn't have auto focus, but I already find myself manually focusing my staircase shots any way. Also the price of the Zeiss is practically 3 times as much as the Rokinon. The f2 of the Rokinon is nice for the astro photography but doesn't do much for the staircase shots since I'm normally at f5.6+. My last concern is the brand. I'm not familiar with Rokinon. What do you guys think?

 

[TreeofLifeStairs]

Morning bump.