The controller is perfect for those who are looking to play PC (Keyboard and mouse) games comfortably.
It is incredibly versatile and functional, and fortunately is still being supported by Steam (Pls don't stop).
The only problem is that using the left trackpad as a d-pad is a horrible experience, but for radial menus and all of that stuff it is incredible, perfect.
The quality of the controller is not good, it feels light and the plastic feels a bit cheap, the shiny part of the controller is uncomfortable to hold, and it is not rechargeable. Trackpad and bumper clicks are really bad, but it can be fixed with a few hardware mods.
You can buy this controller in sites like eBay, it will probably not be plug and play.
Software updates are hard to find, my recommendation is to download an old (Pre-new Big Picture) archive, open big picture, and configure the controller from there.
If you're sick of playing on keyboard and mouse and want something comfortable, this is the thing for you.
Edit: Make a Steam Controller 2 or something