Normal maps require less memory, but they require the object you apply it to to be fully UV mapped, for example, you can't use a normal map on a Vue terrain. In order to use a normal map, you need to check displacement first, which is quite odd...
I successfully imported Zbrush displacement maps in Vue ( since Vue6), but since I don't have ZB, I used free models and mpas from ZB Central (the sword and the humanoid head, if you know them). The maps were GUV tiles (for what this means), and they worked very well, once they were flipped in the Y axis in the function editor ( map size set to -1 in the FE)
Hey! just realizing it's almost midnight in the UK, so Happy New Year, Frank!)