When we have topographic or hydrographic data, we create a TIN or Terrain to further analyse the data (volume calculations, ...)
Since we see Terrains can easily visualise big datasets, we prefer to continue work with this data type. Though we really need the option to delineate the data area, as can be done for TIN's as well.
Another idea can be to have a setting when creating a terrain, defining the maximum length of a 'triangle'.
I currently tackle this by creating a raster of the ascii data > raster domain > Use this domain as input.
Though this is an unlogic way of working.