To roll back a bit... ๐ฎ
If you are proposing to use lots of these in your model - like capitals for columns in a classical building - then component instances will reduce the load on the processing... BUT remember that every facet still needs calculating for shadows, what it obscures etc... So over detailing can be a killer !
If they will never be viewed close up. then it might be better to make a less detailed form and apply mapped textured to the facets to give the illusion of a more detailed 3d form...
See this thread
http://sketchucation.com/forums/viewtopic.php?f=79&t=48892&p=439336&hilit=+molding+texture#p439336
It discusses how to make a detailed cornice, using a texture instead of making every 3d facet...