I visited San Simeon several years ago, and it is definitely a spectacular place. Since there are several tours offered, most covering different areas of the main house and grounds, we didn't get to see the tennis court, but the refectory and the screening room conjured mental images of the star-studded gatherings that must have taken place in those rooms. The entire area is pretty isolated even now; you can just imagine how remote it must have seemed in its heyday.
The 'Building the Dream' documentary is available on DVD from Slingshot, who have a website at
http://www.slingshotent.com/index_html.htm - regrettably, we didn't have time during our visit to catch it in the IMAX theater, but I later got the DVD, and felt that the film probably played better on the huge IMAX screen than on a TV set.