I have also been on holiday to use the router him with a foreign SIM. Also it worked without any problems.
About the Huawei Software (HiLink, the Google Play store for free), the device can be controlled by the device and displays useful information. For example, allows you to customize a data volume limit. On the home screen, the current consumption is then visualized and warns of exceeding and shows the type of network (2G / 3G) and the signal strength. With the Hotspot users connected can also be displayed and possibly banned. Next, you can enable / disable data usage and Roming.
For the Plug & Surf mode, the PIN request of the SIM can be activated and deactivated. If the query has been turned off, the unit will automatically connect to a data network (2G / 3G) once it gets power. In addition, the mini-router is still room for a Micro SD card. This can be enabled for all connected users on the WLAN. I have this feature so far genutzt.Gleiches applies to the operation of a laptop / computer.
Configuration:
The configuration is very simple and well described in the enclosed instructions. The (initial) configuration through a web interface, ie the browser. When you call the "setup" page using a smartphone, there is even a mobile optimized web interface - with limited Konfigurationsmöglichekeiten. Wireless encryption eg WPA2 is possible and works.
I would buy the router again and it - especially with the Recommend software for Smartphone with a clear conscience.