>DTrace, ZFS, Jails, performant TCP/IP stack and many other things where FreeBSD benefits the users.
Just to point out, that DTrace and ZFS are (were) not BSD features, and were not invented by a Open Source BSD.
It just happened that they were open sourced by a GPL incompatible license (CDDL) which makes it impossible to directly merge it into the mainline Linux kernel.
EDIT
Just also to point out that had ZFS been a BSD licensed tech, it's very likely that ZoL would have been just as good an option as ZFS on FreeBSD.
Just to point out, that DTrace and ZFS are (were) not BSD features, and were not invented by a Open Source BSD.
It just happened that they were open sourced by a GPL incompatible license (CDDL) which makes it impossible to directly merge it into the mainline Linux kernel.
EDIT
Just also to point out that had ZFS been a BSD licensed tech, it's very likely that ZoL would have been just as good an option as ZFS on FreeBSD.