Everyone has a take on this, mine is the 14-24. I have tried many other solutions, and come back to it.
Zeiss 21mm, hyperfocal distance is terrible to me until F11, or ever F14. It also not a good lens for night work as it has coma at the edges until around F6.3 and for stacking that's not wide enough. This lens also vignettes pretty harshly until around F5.6 or so. Wide open it's vignetting was problematic for me.
Nikon 24mm 1.4, loved in daytime, hated it at night, has about the worst coma aberration I have ever seen, and stays that way until F3.5 or so.
Nikon 20mm 1.8, still have it, and will continue to use it but it still can't compare to the 14-24 at 20mm. Period. The edges are rough on mine until F8 and the bokeh is mixed up looking to my eyes. Still it's filter friendly and light weight. It's also very very hard to manually focus as the tactual feel is strange.
Rokinon 14mm, Don't count this out. It's a great lens for 300.00. Amazing that they can make such a lens at this price and have virtually no coma at F2.8. It's not of course filter friendly and so it's mainly a night lens for me.
But it's also lightweight, a great carry lens, and a bitch to manually focus IMO. But it can be done. Way too much turning needed to get where you need to be.
Zeiss 18mm, not as heavy as the 21mm, and very sharp. I carry it with all my night trips and most creek work since it's filter friendly. Vignettes very bad wide open, but will correct almost 100% in post. Manual focus is a dream, however it's hyperfocal distance at F8 is about 2x or 2.5x further than the 14-24.
Nikon 14-24. Love it, amazing wide open to F11/F14 on the D800 family. Well past that on a 24MP sensor. Mine has an excellent hyper-focal distance at F3.5 of around 10 feet to infinity, which is much better than the Zeiss 21mm F2.8 Slight vignetting at F2.8 but nothing like other lenses.
It's not filter friendly but the Lee 250 system work fine, but add a lot of cost. But I need filters in my work. I have a modified Lee 250 so I can use a CA Vision CL-PL glass filter in the front slot. If you use the Lee 250 system you really have to remember to use the black out plastic they give you as it's very easy to pick up backwards reflections which will ruin your corners.
Flare is a killer on this lens and you really have to watch for it at all times. The flare from the lens is harsh, and next to impossible to correct. It will be a hard magenta curve opposite from the light source And the lens seems to reach behind at least at 14mm and grab the sun. At night the moon does the same thing, but creates a different but just as hard to clear up flare. It's well worth the cost of a flare buster if you use this lens.
It's heavy, yes, but wonderful across the entire zoom range. I often stitch with this lens, but at 24mm mainly in the vertical. 14mm is going to create way too much distortion in a stitch even nodal and with the camera level.
It's a dream to manually focus, I guess in part due to the huge focus ring.
I will say it took 3 of them to find one that was this good. But I have owned this one since late 2011, and it's been a great lens. Not a lens I would want to travel with on a long trip however just due to the weight, unless I knew I was going to be shooting at night. This lens is a night photographer's dream, if you remember to watch for flare.
Paul