Just my 2 cents. Qnap are useless. Overpriced hardware (not that Synology is not!). Desktop components in server chassis (even on the high end "Enterprise" models!)
OS on Qnap is wonky at least (would never trust my data with it again).
You want good NAS, use proper hardware (HP, Dell, Lenovo) and put Server 2012 R2 on it! Job done