Unlike its predecessors the AFS 105mm f/2.8D VR is an internal focusing based design which means it doesn’t change its physical length when focusing and the front element does not rotate, making it easier to use with a circular polarizer or other attachments such as the R1C1 wireless Macro lighting kit. But as already mentioned, the penalty for this is "focus breathing". Unfortunately, the new VR version being a G lens is not compatible with the PK series rings or old bellows.
All of the Nikkor macro lenses are similar to variable aperture zoom lenses in that the aperture value will vary, in this case according to focus distance and not zoom selection. As you focus in the macro range the camera body will display the effective aperture and not the actual aperture you had originally selected, so reaching the maximum magnification of 1:1 will result in a decrease of the maximum aperture from f/2.8 to f/4.8.