Once you figure it out, Zorbec's is hands-down the
best deck builder. Really.
However, its database is built into the program, so it's not so easy to add new cards.
SdA, on the other hand, is a bit more flexible. Some people used to tell me that if you modify the SdA data file, it could caush crashes when it finds that an opponent doesn't have the new version. Since it isn't being used to play as much anymore, I don't see the harm in using it to be a supplementary deck builder for GCCG and adding any new cards.
Also, it's always a good backup method to play for those who can figure out the port forwarding and such.