This might be worth a watch. I'm not even going to recommend it because I haven't watched it yet. But come on, it's bound to be awesome. 
 

Well I'm halfway through and I have to say that although it's as cheesy as hell and some (most) of the music demonstrations are like having molten steel poured in your ears, I'm strangely fascinated and amused. 

Well that was both interesting and awful. It's well worth watching the last part (part 4) for some excellent footage of a young David Vorhaus in his studio though. 
 
I found this great interview with Vorhaus from 2002 in Sound on Sound, in which he talks about (among other things) embracing Reaktor as a more convenient way of experimenting with the kind of synthesis that used to take him months with analog electronics:
 
http://www.soundonsound.com/sos/feb02/articles/davidvorhaus.asp