I have a feeling that it is NOT for sites over 200,000 pages.
My site is about 1,000,000 pages. Now that I am at about 230,000, it is very slow, and freezes up each time I run it through ssh after about 2000 pages.
I could not imagine starting and stopping, starting and stopping, every couple thousand pages, for the next 780,000 pages.
Plus it REALLY bogs down the server at this high level also.