Question re cardigan vest neck opening

I am looking for a red cardigan vest for the fall. I have come across several, the photos below being representative of what I am looking at. During my search, I noticed that the size of the neck "opening" (Is there a term for this?) varies greatly in length, down to the first button.

I like both, but I would love to have some input from members regarding your preference, and why. Which do you prefer? Thanks a bunch.



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Question re cardigan vest neck opening