I'm sure there are people who can hold the D800 steady at slower shutter speeds and get excellent results. I'm not one of them.
If by "excellent results" you mean the "internet forum" definition of sharp 100% crops, I'm not sure that anyone can consistently meet that criterion. Nor is VR and lens testing a comfortable combination; I see its purpose as to create "good" printable shots rather than trying to reach optical limits.
Lots of things work against the home lens tester, starting with the home itself. Most floors can impart their own vibrations; those that don't (such as bare concrete) are rarely the most comfortable nor the best lit places to test. Not do all that many houses have the longer unobstructed "runs" which are desirable for testing telephoto lenses.
Next comes experimental error. Even the best designed and executed test is going to show some variability, and rather than using specially designed expensive instruments, most of us "make do" with adhoc rigs and perhaps a couple of hundred dollars of test gear. When the test requires an uncomfortable or awkward setup, or constantly readjusting physical layout, it's still valid in theory, but it takes a lot of samples to get any reasonable idea of what's going on.
Finally, there's the ugly spectre of observer bias. I know I talk myself into seeing things the way I want them to be -- I have several coins in my coin collection which I should have returned and didn't; I'll lose hundreds of dollars on each on resale. I've talked myself into photo gear as well; it would be naive to assume I can't talk myself into the test result I want. Yet all too often, I've seen posts where people make claims which are either physically impossible or extraordinarily unlikely and then take a suggestion of an independent retest as a personal affront.
One of the biggest mistakes a photographer can make is to look at the real world and cling to the vain hope that next time his film will somehow bear a closer resemblance to it. - Galen Rowell