Chuboy, I would think that pilots being pilots would use the ILS especially if they're tired. The usage rate of the iLS will start of as a trickle and end up in a flood.
The bit that interests me (amongst other things about this project) is what will be the ILS minima for this particular airport. From what I understand the RNP is limited in its minima by terrain. Would the ILS not be as restricted ??