I'm still having some trouble; I was able to install FreeNAS on a thumb drive, after I'd allocated the disc space, and setup CIFS sharing, etc.
The issue I'm having with my Gen8 is that the network will 'die' when transferring large files. For a while, with say a smaller ISO, 600MB or so, the transfer works. If I throw a larger file (2GB+) it will begin to transfer normally, and then the NAS device will be come 'unavailable'. I do not see that FreeNAS has crashed, I can still use the web console, but the file transfers look like they're complete when I browse the NAS, but I know that they've not completed successfully.
Is it a network card driver issue? 8GB of ram in these boxes. I have two of them, same install, same result.