Terrain as a 3d model would reduce performance issues by 90%, because it is a single object. This would also remove brick lag, and ghosting completely for users with less powerful PC's. Terrain Generators by brick put much more pressure on your GPU and CPU, as well as a very long ghosting time for newly spawned players. If you notice when spawning in-game, special bricks tend to load before bricks and plates do. The same principle would work with this terrain.
 A new concept has been brought to the gallery, by using a LUA scripted height map editor 
here. Although this may be more compatible with bricks, this could possibly work with a static object. In his "Planned Features", he mentions size and object editing. If the terrain is made into a very large brick, it could be edited by vertices, or edges. If this is converted into an add-on, it may be possible to generate objects, instead of using bricks.