I have had great results from the Tokina 17-35/f4. If you don't mind the weird distortion, the OLD nikon 18-35 is a fairly sharp lens.
Not long ago I picked up an Irix 11mm/f4. It even works well with a 1.4, teleconverter, yielding a 15.5mm/f5.6. Perhaps I received a good copy, as I have not concurred with many of internet's negative reviews. I purchased it for close to half price, so my opinion, reflects.
I had both the 2.8, 20mm, Nikons, af and ais. I cared for neither. I use the old 20/f4 and use the hyperfocal scale, for landscape. What I usually try to do is purchase used/(best price/condition,) and if it turns out to be a turd, toss it back, sell it on "that auction site."
The D3x is a wonderful camera, BUT, it is a totally different cam, compared the original D3. (The D3x is the "pro body," with Nikon's highest megapixel count.)
Best Wishes.