I have been running this NAS for 14 months or so. The latest OS is faster on Macs. It provides good files services to Mac & PC Windows plus extra services like Indexing of Films, Photo Server, Cloud server, Download server Virus scan etc.
The support from China is very good if you have any problems - eg power cut during upgrade. Generally very stable.
Once Windows (XP, 7 etc) is setup on Parallels Desktop 9 on Mavericks OS X then it is more stable than many PC Windows setups. I have had one USB device (a 3G modem) not work but many have - including a TV USB stick with HD (in the UK that requires DVB-T2 not supported on the Mac yet).