I've now read 2 articles in the past few days about complaints on not being able to add or update previous entries on PCGS coins. For me, this is why I started my registry set as well. And I too fell it is complete BS. We can't even update the existing PCGS coins.
Personally, Now that NGC and PCGS only support there own coins and only allow there coins into there respective registries. I would like to see another company start a "combined registry" of both. like NGC was. its a service I believe it was something LOTS of us were using, and we may even pay for to show off our collections.
I have way too many PCGS to try and cross them over, and I'm sure, only 1/2 of so would go anyway. It would cost a small chuck of change.