With these features, Solaris 11.3 is the current ZFS champion. If you need support, it is an alternative to OmniOS. There is also an edition with a GUI or for Sparc. While I would not see Solaris as a desktop option, this may help to simplify management. If you use it for demo and development (no commercial usage) it is really attractive..
If you use it commercially or in production - may be even university use - especially with more than one server and if you do not need paid OS support (but want it as an option), OmniOS is very attractive as you can use it for free even commercially. The most missing current item is SMB 2.1 with the Solaris CIFS server (SMB3 is available via SAMBA) that is on the way as Gordon Ross will upstream this feature from NexentaStor. (From his own statement in the Illumos dev mailing list: nearly ready)
Product Details - Oracle Solaris Premier Subscription for Non-Oracle Hardware (1-4 socket server)
At last, you must decide to follow OpenZFS or closed ZFS.
In my own university setups I stay with OmniOS despite the fact that I want SMB 2 and up for my Macs.
