Buy for the Shift Key Option
With the Xbox Accessories App you can set one of the buttons to be a shift key. This allows you to assign a secondary function to the other buttons.
This way, you get more controls at your fingertips in intense games or in games where you often need to rely on a button or a press that is difficult to get your fingers to in a timely manner.
You can also assign buttons to record that or take a screenshot in the app. This is a great way to use the shift key modifier.