This is a great read as I’m currently in the same boat. Should I pay the premium for CBI or go for ACA question...
My vote is if CBI if you prefer that stone. I would pay the premium. The premium may also include crossing the carat mark line, which by the way, I am in favor of. I am not a fan of .99 stones, but that is me, and I mentally need to know my stone is of a certain weight. The price difference will be nothing in a few years, you would have forgotten about it, but now you will have that fabulous stone.
Did you see the other thread on ACA vs CBI? The OP of that thread @erislynn chose the CBI and her stone is fabulous. She posted great comparison photos and explanations:
https://www.pricescope.com/community/threads/cbi-vs-aca-another-pic-and-vid-comparison.236493/