FWIW (since it seems none of us have the same experience with CP schemes) Waves Central was probably the easiest upgrade I've had. Everything kept working, and I could easily move licenses around, and keep track. All in all a painless experience.
Now I am (as always) skeptical about all the recent security updates - Waves Central, iLok, even eLicenser, and now it appears Plug-in Alliance. On the one hand I'm pleased they are paying attention, on the other hand I do tire of worrying about security on the studio computer. (I'm betting the recent CCC update had something to do with security too, but I'm too polite to ask!)
So we'll see, if I run into any problems (tonight is the big update everything night) I will report back here, otherwise I'll be too busy making music to post! I hope!