It doesn't matter if it is a tele or wide - the adjustment basically pushes it up or down based on the focal length. Neutral is usually Shutter = focal length and it moves the ISO from there. The adjustments then push up the shutter 1-2 stops in either direction.
It works quite well. I do wish it would "remember" my settings for each lens as for VR lenses I can adjust down a couple of stops vs. non-VR.
Of course if you want a "look" the camera can't tell you do, it just always wants to get the "proper" exposure. I do like the button layout on the D800 - I can change every setting from the buttons very quickly for manual exposure and do not have to dive into the menus.
D800 is not a journalist/sports photographer camera. If it were the D4 doing this - where the photographer has to get the necessary speed for freezing the action or getting the shot no matter what the quality, I would understand the compromise that comes with increased ISO .
D800 is a 36 Mp camera and its strength comes from the detail and IQ it offers. When it is a fact that minimum ISO = best IQ, I can't give credit to Nikon for its preference to use AUTO ISO this way - unlike previous cameras. It is giving very little control to the photographer.
And it is annoying to see AUTO ISO managed different ways in different cameras. The D5000 came with different Auto ISO behaviour than previous models in flash mode. Now with the D800, you have to remember to be in S mode if you want traditional Auto ISO - ( which chooses lowest ISO when possible )
A minor detail for most probably but as someone unable to understand why Auto ISO is not automatically turned off in MANUAL mode ( in previous models ), this is just another annoyance ( for me ) to get used to - in probably all new Nikons to come....