I just think that in the mix, I can get a better, more subtle stereo image. If I used all the stereo features on the Virus, and all the stereo things I can get out of Reaktor and MaxMSP, things would be crazy, and I think kind of silly. a more subtle stereo mix from mono or near-mono sources "fills the room" better to my ears, and to how I want my music to be heard.
obviously, there is a middle path between MONO! and crazy bouncey stereo stuff, and really there is a place for both.
regarding the Capistan, I've really dug the stereo image it puts out.