I wasn't talking about quiet mode 
Quiet mode specfically slows down the components of the release cycle (mirror up, aperture closing, shutter open, shutter closed, aperture open, mirror down) so you get less intense sound but the "dead time" of the AF system between shots increases, thus your continuous focusing on moving subjects works less well. In my opinion, impairing the AF performance of an action camera to reduce the sound intensity doesn't make sense, unless it is for a specific situation (such as a concert) where AF tracking performance is less critical since the subject moves less fast, and for this situation they offer the quiet and silent modes.
If I use a smaller than maximum but still continuous fps rate in a fast camera, I do it precisely for one reason and one reason only: to get better a higher AF keeper rate, by giving the AF system more time between shots to do its thing. Slowing down the release cycle would counter this goal. I am normally a single shot shooter, and one of the reasons I never liked high fps on the D3 was that it couldn't really keep the focus on the subject in an approaching subject scenario at a wide aperture, if I used 9fps. By using a lower 5fps or 7fps rate the rate of success increased a lot, and this is because the AF system had enough time with the mirror down between shots, to keep the AF sufficiently on the target. I believe the AF system continues to focus even while the mirror is up but it gets no data on the subject distance so it basically is operating under the assumption that the movement is constant velocity or the acceleration is constant. If the movement changes velocity in an unpredictable way then the way to improve AF results is to speed up the mirror movement so that the mirror up time is as short as possible. Shorter mirror up time is one thing I recall Nikon advertised for the D4s already, so I have high hopes the D5 will be similar or better. I'm much more interested in the AF performance than high fps rate actually, as I prefer to time my shots manually except in unusual circumstances.
In a camera like the D810 the camera can be quieter because the main intended application is not fast action (but the highest resolution and image quality at low to mid ISO), so they emphasized low vibrations in the design, and the side effect of that is quieter operation. I suppose they could put in a semi-quiet mode in the D5 where things are slowed down a bit (not as much as in quiet mode) but then it would be really difficult for photographers to adopt to the effects of the changing settings depending on fps rate selected. I think most sports photographers would primarily elect to get the best AF rather than ever so slightly quieter operation. For wildlife photographers the D500 may be the better choice as the mirror and shutter are smaller and you get more pixels on the subject with the same lens. The D500 felt very impressive in the hand and the release cycle is quieter so perhaps it's the better choice for daytime wildlife photographers. DX is quite elegant for telephoto work in my opinion.
In a hide I would expect that using a blimp would be possible, with the lens on tripod. This would probably be a less distractive approach to the animals than shooting in the open in any case.
