I notice that this uses the same chipset as the Alfa AWUS036H that I have been using and am very happy with.
If the software that comes with the Techex does not have power adjustment, you might find that the Alfa software will work with your unit. The ability to raise and lower the power both saves your battery, reduces interference to others, and prolongs the life of the transmitter, as it can run hot at maximum power.
Alfa Driver Downloads
Another feature of the Alfa software you might be able to take advantage of, is the virtual WiFi hotspot, which lets other nearby laptops, iPhones, etc share your long distance connection - handy if you travel with a partner with her own laptop, or want to use your smartphone's WiFi connection to transfer data, etc.