Just wanted to echo how great it is that Softimage allowed these to be made available. These include the DVDs that I got back in the days of Foundation 4.0 and they contain an incredible amount of great information, and it's still very helpful even at version 6.x.
The situation with regard to books on XSI is really quite pathetic at the moment, but these videos as well as the very nice tutorial video products from Digital Tutors (and a few others) make the self-education situation for XSI really quite excellent.
Thanks again for making such a great tool and these resources available.
F. (also a happy XSI Essentials user)
P.S. This information should be stickied somewhere if it isn't already
