I use the DK17M on the D2X and it has been really nice compared to the original. I figured I would put it in the 700 and see exactly what I'm dealing with before ordering another. The 700 will display the tilt angle of the camera on the right side in the viewfinder and first I want to see if it is of much/any use to me, because a DK17m will push it farther into the periphery.
I think a hand strap is more of a situational aid than a necessity, but great to have access to when needed. Most times I prefer to have nothing at all because the bulk of my shooting involves a tripod, where straps become a liability. I'm sure that in this case (D700) where the higher ISO's are actually usable and shutter speeds increase I will be able to shoot more without suppor, or with the mono pod where a hand strap would be nice.