I think that in order for GHOSTBUSTERS III to hit gold it MUST capture the feel of the original film. One of the things the makers must do in order for this to happen is drop todays technology and go back to the special effect making methods of yesteryear.
The star wars prequels, die hard 4.0 and kingdom of the crystal skull are proof positive that although the cgi may be more advanced it just destroys both the look and feel which were in the films which preceded them.
Doing Ghostbusters III the old fashioned way would be great because firstly it will make the new film fit in more with the films which preceded it, people will have more of an appreciation for the sfx, it will make the film feel more nostalgic and also it will make the film a little different from all the other sfx movies which come out these days.