The Bluetooth pairing is easy, my phone Samsung Note 3, the keyboard is directly recognized QWERTY.
Reconnection is automatic as soon as you tap a key on the keyboard.
By cons, as many keypad, Android 4.4.2, special characters do not work: the top line "1234567890" provides only numbers. Can not have an "e" for example.
Then, looking, you can download the Androidd "physical Qwerty keyboard" application but it requires you to choose every time this keyboard in the settings manually before using your keyboard. Just painful.
I contacted Samsung has confirmed that its keyboard is not fully compatible with its own products ...
So if you want to take a bluetooth keyboard, take a half the price, it will do as well / as badly.