After palying Fallout 4 for a while, yes the map is a bit on the small size, particularly compared with FNV and Skyrim. Missions are starting to repeat, where I am having to keep clearing out the same areas again; feels a bit like an XCOM Enemy Unknown type game where you keep repeating the same maps all the time. This did not happen to me in FNV and Skyrim, so a regression.
While I like the idea of having areas respawn, to keep the game populated, I don't approve of using this as an excuse to skip on world size by keeping repeating missions on the same area.