Thank you for your response! I will also need to lengthen the chain. Did they keep the original two jump rings and added an additional, third one? Or did they lengthen the chain and keep only two jump rings, just at "longer" positions (sorry it's an awkward wording, not sure how to articulate this differently)?I got my cdc in March and have worn it everyday since. It is 0.5c in yellow gold. I was debating between the 0.35c and 0.5c as like with your sizes, there is a significant price difference. I ended up not liking the rose gold on the 0.35c since my jewelry is yellow gold. I didn't notice in the store, but in my home lighting, the coppery tone was more distinct, so I ended up exchanging for the larger size so I could get yellow gold.
From my experience, I can say that the 0.5c is a great everyday size. It's super comfortable and lightweight, I have no problems sleeping in it. I did also have the chain lengthened.
However if you are already concerned about having regrets over the smaller size of diamond bc diamond shrinkage is a thing and you can afford it, it's best to go with the larger size. You may initially think it's a bit big and flashy at first, that was my concern with 0.5c, but you'll get used to it in time. I feel like people rarely regret going larger when it comes to diamonds, but much more often regret going too small.
Also, when I tried these on, especially the larger stone, I noticed that the pendant was sort of flipping towards me, if that makes sense. Maybe due to the curved C design on the back of the pendant, the stone was kind of facing towards my chin more than towards the mirror. It wasn't too bad, but definitely not ideal . Do you experience this with your necklace?