Which NAD83 datum should I choose when creating a layer?

Almost always, the selection of a NAD83 based layer in older versions of GeoCue (pre v2011.1) NAD83 was used to refer to the then current NAD83 datum, for instance NAD83(CORS96) for most early LIDAR collections, and subsequently NAD83(NSRS2007). The current realization of NAD83 is NAD83(2011). All of these realizations are available for selection in GeoCue 2011 and later. For more information on the differences between these realizations please refer to NGS.