There was an issue with my KOR V2 so my dealer offered me the opportunity to swap. While I had initially committed to the 40mm, I was always very skeptical about the sizing..
Since the opportunity came up to switch to GF (which offers the 35mm, not to mention cheaper) I decided to once and for all figure out the appropriate sizing for myself before deciding.. I went to my local AD and checked both the 35mm and 40mm on both bracelet and leather strap.
Apologies for the picture quality, I always find AD lights too intense and makes it very difficult to take good pictures.
For reference I size around a 6.5" wrist.
First we have the 40mm
Then I tried the 35mm
Side by side of the 40mm and 35mm on bracelet and leather:
In conclusion... Frankly I left just about as uncertain as when I walked into the AD. I felt that I could quite easily wear either size.. both 35mm and 40mm sized quite well on my 6.5" wrist
on bracelet. The 40mm features a slimmer case than its predecessor, the Santos 100 XL (which personally I found too large, and subsequently sold).
The new larger 40mm Santos De Cartier doesnt feel too bulky on wrist with the bracelet. However once I switch over to the leather strap, it reminded me a lot of the previous XL, and I felt it looked too big, especially on that square case. It was interesting that the effect of the leather made the watch look bigger on wrist..
However, I noticed the opposite with the 35mm. On the bracelet it sized quite well, a bit on the smaller size but I felt it added to the elegance of the watch. I feel it is a good versatile size with just enough presence to be worn for various occasions. Once I switched over to the leather strap, the 'bulk' that I felt was carried by the bracelet, completely disappeared. The watch suddenly looked very small and (imo) slightly effeminate .. It was so strange to me that the leather made the 40mm look bigger, yet made the 35mm look smaller.
In the end I did decide to go for the 35mm and have confirmed to swap my KOR V2 40mm for a GF. Not only is it a much better deal incl. the leather strap, I felt that I have already experienced a larger sized Santos with the XL and while I realize the new 2018 Santos is a much slimmer case, it still carries a very similar wrist presence. The smaller Santos on bracelet wears very well on my wrist size, and I already have a lot of "bulky" sports watches in my rotation, will see how it goes experimenting with something smaller.
As a bonus, I have been trying to get my girlfriend into watches. This might be a nice opportunity if she wants to give it a try .. haha.