Linux is superior in hardware support and the amount of software Linux can run, which it not trivial, but beyond that FreeBSD and Linux are about equal in performance and capabilities when it comes to being a server. Also I would say that containers(jails) on FreeBSD is better than containers on Linux in terms of security. FreeBSD also has a more robust COW filesystem(ZFS) than Linux. The Linux crowd will get btrfs or an equivalent filesystem battle tested in the future because they are smart, but ZFS is currently the more battle tested filesystem.
Also when Netflix's open connect team finally open sources TLS sendfile than mainline FreeBSD will have much better file serving performance than Linux does. The FreeBSD downstream fork running on open connect appliances was doing 100Gbps of TLS encrypted traffic last year and I believe are doing much higher now[1].
Finally for me when I first got into Unix and Unix like operating systems I found the huge amount of Linux distros to be hard when it came to documentation. Generic Unix commands were pretty much the same across distros, but each one had a different package manager and different filesystem layouts, and different ways of upgrading, etc. With FreeBSD you just look up FreeBSD directions and don't have to worry about differences between distros.
Also when Netflix's open connect team finally open sources TLS sendfile than mainline FreeBSD will have much better file serving performance than Linux does. The FreeBSD downstream fork running on open connect appliances was doing 100Gbps of TLS encrypted traffic last year and I believe are doing much higher now[1].
Finally for me when I first got into Unix and Unix like operating systems I found the huge amount of Linux distros to be hard when it came to documentation. Generic Unix commands were pretty much the same across distros, but each one had a different package manager and different filesystem layouts, and different ways of upgrading, etc. With FreeBSD you just look up FreeBSD directions and don't have to worry about differences between distros.
[1]: https://medium.com/netflix-techblog/serving-100-gbps-from-an...