As modem very good, as a router rather mediocre

As a pure VDSL modem (Bridge mode) makes the Zyxel a good figure, tested with pfSense on a 50 telecom connection - no crashes, faster sync, excellent connection (average 47.5 Mbps in download and 8.5 upload speed when tested at several servers, Ping ~ 15ms). In other downstream routers but this need not be the case. An extended test with a subsequent TP-Link WDR3600 suggested example will fail. In full-fledged router mode the ZyXEL VMG1312-B30A works fundamentally - to put it mildly. The VDSL connection was set up quickly. The WLAN performance is sobering - for a floor's enough. The functional scope is impressive - only the implementation and administration is what winded up incomplete. WDS works after last documentation with Zyxel products. The admin interface is implemented as standard said cautiously, now and then every third click an error message "Bad Request" of the ZyXEL internal Web server. Can you get over, at the price, however, that should not happen. One gets the impression that they have once again caught a banana product. Anyone who thinks a Fritz box or to replace a Speedport so, in my opinion, comes from bad to worse ... three points I will give for the Bridge function and good VDSL connectivity - zero for the rest.

Addendum: It happened that the unit (with factory settings) after switching on (eg after power failure) does not start (all LEDs remain permanently in a state). Pulling the power supply is also not a solution (before suspicions arise, the power supply it is not). From this state can free itself by repeated and rapid power on / off - the device seems then to start again normal. Resetting to factory settings brought here ultimately healing, implying a software or configuration issue. Since I generally only use the factory default settings (as VDSL modem), I do not guess times on a misconfiguration on my part. For a mid-range device may expect something more reliability. I would deduct a half a point.