If you want to buy and wait, buy it from JRR shop or Sweetwater - then you lock in the upgrade price but only start the 12 month membership when you have time to redeem the code and run the installers and get into it.
The CCC is great, easy as pie even though I wish it had a pause button. I left it downloading the DimPro install and went out, came back to a hibernated computer and when I fired it up, the installer cheerily told me that everything was done. That's my kind of upgrade process.
The upgrade is excellent value IMO. Basically seamless transition but generally just better, and a few key new toys in there to make it fun to explore. And 12 months of goodies still to come, which we 'own' in advance... an embarrassment of riches, really.