Potentially allowing un-encrypted child datasets & Zvols, of encrypted datasets
Linux kernel 5.x optimizations, (lots of stuff in the kernel is now enforcing GPL... or other weirdness)
DRAID new vDev type, (integrated & distributed spare, allowing extremely fast sparing)
Even with the official release, the old saying goes, never use 1.0 of any software. So I'd wait til 0.8.1 or 0.8.2 to make sure enough of the serious bugs get fixed, before I'd start using 0.8.x.
I am happy to see that the ZFS on Windows project had been keeping up with the various features. Have not checked recently... but this feature matrix seems to be reasonably up to date; OpenZFS Feature Matrix