I don't know about WebAuthorize, but dealing with Cybercash has been a chore since their acquisition by Verisign. A couple of months ago I was trying to bring an existing Cybercash site onto a new e-commerce package, and encountered major confusion and support issues. Even the web site was changing, which meant that the support info that was available a few days before now couldn't be located.
I'm assuming things will settle down, but I wasn't overly impressed by my experience.
yeah the Cybercash acquisition did not go very well at all. Verisign just built a wrapper for the cybercash system and it sorta worked. We wound up just signing up a new PayFlow Link account at Verisgn and rebuilt our shopping cart - works much better now.