Much of this is covered in the links above by people far more knowledegable than I am.
Therefore, this page will be aimed specifically at those who use Fedora, and what might surprise them.
The upside is that one finds fewer desktop oriented thinking issues, such as Red Hat deprecating its text installer in favor of the GUI.
The downside is that there is less manpower and energy on some things like Linux users take for granted.
To cover it in a few sentences, userland and kernel are all produced by one group, whereas in Linux, Linux is really only the kernel.
Everything else, such as the shell and various commands, are made by someone else.
Some programmers feel this gives them more freedom.From time to time, on the Fedora forums someone will ask about BSD.This article is a rather superficial overview, attempting to focus upon the main differences a Fedora user might find.If you wish to take their word that it's not worth the time and has a bad license, then that's up to you. To be fair, the Free BSD forums, at least, have also gotten nastier about Linux.To me, it's sad, because both have relatively small market shares and if there was more combining of forces, it could be beneficial.