Great info on the BushHawk. Once I finally get my 70-200 VR II I'll have to seriously look into this setup. May have to put the 300mm 2.8 on my wish list as well.
Though not near as stunning as the other images posted here, I have had some success using the 24-70 2.8 with the D800E. Will be nice not to need such an extreme crop but good to have the option available.