I published my tetsing with three different cards in one of the discussions
last week.

Although the group came to a consensus that high speed cards are not on the
official NIKON list for either the 5700 or 8700, in my tetsing I readily
observed differences of 30 seconds or more between one card and another.
This can only mean that at somepoint the camera does support faster cards,
but what the actual cutoff point is is yet to be determined.

We think that it might be around a 12X card, however, costs are coming down,
so if a 40X card gives you a speed boost, enjoy.

Try to find a dealer that will let you test the card to be sure you are
getting a speed boost.

I cannot find my earlier posting.