I have had several Tokina lenses and they are constructed as good or better than a Nikon lens. I have the Tokina 16-28 f2.8 lens at present and it is better than Nikon's 16-35 f4.0 lens.
I am renting the Tokina 24-70 f2.8 lens and although it is heavy, it will surely be well made with excellent optics. I will purchase it if it works well for me. I don't care about lens stabilization, just something else to break and leads to sloppy technics in making images. I have tried Sigma and Tamron, but think Tokina is the way to go for third party lenses.
I'm too busy using my d4 for the last several months to read reviews. Dpreview seems stuck on the d800 and d600. All I can say is that the d4 meets my needs for a super high iso camera, excellant build, af excellant and frame rate fast amongst a lot of other improvements. It is a pity that dpreview has ignored the d4. Maybe because the d800 and d600 brings more hits on their forum?