Cons: Bought this at another store thinking it was an Atheros chipset. Turns out version 4 switched to a cheap Realtek RTL8192CU chipset. The speed is unacceptably slow 3.94 Mbits/sec on Linux kernel 3.12 measured with iperf. Binary drivers are not a solution for Linux. Look elsewhere and get an adapter with a good radio.
Cons: I was looking for this model, but the v2 not the v3.1, since the chipsets are different. The older chipset is compatible with a fully free distro of GNU/Linux, but the newer one is not. I got the newer one, so I had to return it.
Summary: This 11N wireless adapter receive a much better signal than my zonet 11g wireless adapter and data transferred from the router is stable. It does require software installation to be recognized by Windows 7 64 bit. Excellant adapter for the price.
Pros: Strong signal, fast, Windows 7 64 bit compatible