I need 802.11 n for speed and discovered, that nearly all 802.11n adapters require firmware!
For example, Ralink - rt2400usb driver will just initiate the adapter, but it won´t pick any connections!
So, I am forced to download driver manually and compile it, and recompile if kernel get changed.
All these difficulties by side, running firmware in insecure and dangerous investment over time.
So I decided immediately to RMA the device and seek advice.
But, for example, another option - Realtek: according to Debian is also proprietary.
Do you know any chipset vendor for 802.11n that is worthy of investment?..