Bowman on Avatar

"What [Yoon] means is that the feelings of discovery and delight and, on leaving the theater, nostalgia that even ordinary moviegoers appear to be getting from the film are exactly like the feelings biologists get from the real world.
"Except that, of course, this cannot be true either.  'The naked, heart-stopping wonder of really seeing the living world' simply cannot be unconnected with the fact that it is the living world and not some computer-generated simulacrum of a living world that is not, in fact, living at all."

James Bowman, "Avatar and the flight from reality," The new Atlantis: a journal of technology and society no. 27 (Spring 2010):  3 (http://www.thenewatlantis.com/docLib/20100303_TNA27Bowman.pdf).
Although I may well come to look back on this as a little dispeptic, Bowman is surely onto something here.  What is the difference between Avatar and Perelandra?