From someone who has done heavy development on both - I would say it's quite difficult to get used to the filesystem, non-POSIX (which is why mac users and linux users tend to find affinity), windows API being a bit arcane (Things like user-groups, event viewer, and process explorer being mostly dated UI apps with unique and strange windows API calls), services vs daemons, session-zero.

I would say it's great at a user level, but under the covers you have to be a true windows grognard to know what is going on.