I bought mine because apparently the Steam Link now supports this controller which is almost the same as the X-Box controller that I use with my PC. Also supports PC connection too with firmware.
Considered to be one of the best third party controllers for Android Bluetooth gaming on the go.
I've not found a decent third party wireless controller that works on the Steam Link for less £££ and I've been looking! Let me know if you see it cheaper elsewhere or have any recommendations!