I got mine THL W8S working satisfactorily. Three things are required:

1. Activate AGPS.
2. Enable Auto EPO downloads.
3. Select a local NTP server (default is Chinese)

There are a number of apps and tools to achieve steps 1 and 2 (Eg MobileUncle)
However step 3 I think requires root access (edit gps.conf file in Root Explorer), or some means of flashing a new gps.conf file to system\etc

Anyway, hope this helps.