I purchased this device to connect several laptops to the internet through one 3G modem and have discovered that it can also be used as a range extender or an access point with the flick of the switch on the side.
I had to install the latest firmware before it would detect my 3G modem: the Troubleshooting section of the Quick Installation Guide tells you were to find the firmware updates. Clear instructions, which I suggest you read, on how to install the update are provided. I also had to do a little tweaking of the modem settings manually since my configuration does not appear to be a standard set up, this was easy to do (although you have to know the correct settings) and, in any case, will probably not an issue for most cases.
In summary, it is small and portable, can be powered either from a USB port or with the supplied mains adapter, simple to set up. The instructions are easy to follow (in spite of clearly having been translated in to English), and it can do everything I wanted it for and more besides at a cheaper price than bulkier hardware that can only do half as much.