I agree that LCS seems a lot more compact. The missions and locals felt closer. Maybe that is why I like VCS better so far (just starting playing), it is more similar to the console versions because if seems larger. Only issue with that is it takes more time to get from point A to point B compared to LCS.
Can't really say much on the story of VCS, seems alright to me right now. LCS is pretty good, I hated the characters but that was kind of the point.
So if quick sessions is what you want, I'd go LCS.