zoom lens focus adjustments vary with the focal length, my results:

I calibrated my Nikon lenses with my D800 and Focustune (which is easy and a joy to use).  I tried 3 different focal lengths for all the zooms to see the differences. I used a tripod, mirror lockup, shutter 2 sec delay, and cable release.

THe only major differences were with my new 70-200 2.8.  Do you think these results warrant a return to Nikon for this lens?

FOCUS TUNE adjustments (* lengths had the most fine tuning):
1. 24-120 f4, set to -3
    @ 30 mm 0
    @ *85mm -3
    @112mm -5
2.  14-24 f2.8, set to -5
    @*14mm -5

@*20mm -5
    @24mm -4
3.  70-200 f2.8, set to -10
    @75mm  -10
    @200mm -4
    @*122mm -16
4.  18-35 f, 3.5-4.5, set to -7
    @18mm -5
    @23mm -5
    @*26mm -7
    @35mm -10
5.  10.5 mm f2.8 dx, set to -6
6.  80-400 4.5-5.6, set to -5
    @400mm, -5
    @*240mm, -6
    @80mm, -5