rndc unfreeze vs thaw

[SilentRage]

I've been a heavy user of the freeze/unfreeze commands since I excitedly installed BIND 9.3.0rc1 a day after it was released. It's played a very important role in my dynamic update capable multi-user system. Now that I recently upgraded to the final version of BIND 9.3.0, I am looking at this deprecation of the unfreeze command. I've never had a problem with its performance so I don't know why I should change my scripts to use thaw. In all my googling and grepping of documentation I can't for the life of me figure out the difference between unfreeze and thaw, nor the motivation behind the change.

Could anybody offer the answer to these 2 questions?

Dave