I bought this lens because I wanted something with the capability to shoot extremely wide. I mainly use mine for indoor group shots, room interiors and architecture. I also use it for landscape, but I tend to use it only tripod mounted and use exposure bracketing methods rather than graduated ND filters, as this lens is not a great candidate for front mounted filters. It is possible, but you either need to create your own DIY filter holder, or you need to buy a very expensive commercial solution. For this reason, you have to concede that this isn't Nikon's best lens for landscapes. Screw-on UV filters are a non-starter. If you're primarily a landscape shooter, I'd suggest looking at the old 17-35 f2.8 or the new 16-35 f4 instead.
Where this lens comes into its own is for capturing group shots indoors using available light or flash, close-up reportage shots (think paparazzi) or architectural shots where you're not looking to correct for perspective distortion in-camera (if you need that, investigate the 24mm PC-E).
The 14-24mm f2.8 is simply breathtakingly sharp across the frame, exhibits no vignetting, and minimal distortion. I absolutely love it's ability to squeeze every last object in the room into frame. Estate agents will adore it, as you can make a tiny room appear cavernous!
Of course, because you can't install a front filter for protection, and because the front element is so large and so exposed, you need to be very careful how you wield it, and if there's salty spray or beer being thrown around - you might want to think twice about using it in the first place.
Overall, this is just unbeatable when you need to go really wide and you still want to capture gorgeous, sharp, contrasty shots with a minimum of glare (the nano crystal coat takes care of that) and have the ability to open up to f2.8. As I said, not the perfect lens for landscape unless you use exposure bracketing, but for just about everything else it's unbeatable.