I have the Steam Controller.
While I cannot recommend it for certain games, I can now recommend it for Tree of Savior.
Initially, it did not work well. But a firmware update from Valve has made it possible.
The Steam Controller is now not only functional, but it feels really nice with some of the profiles some users have created (Though they were intended for the XBOX360 gamepad).
But basically it now uses the right touchpad as your mouse cursor and the L3/R3 buttons as your left/right click (Which is essentially the function of the mouse). The R1 key (Or pressing down on the mouse touchpad) will bring up your rest menu. The L1/2 and R2 when held down, bring up your actions. Double pressing in any direction with the joystick will make you dash and use your stamina on Swordsman type of classes.
Without holding anything down; the A key is jump, X is your attack, B is used to talk to NPC/interact with objects and Y brings up your item menu (Or you can bring it up by using the mouse functions described above).
Essentially, it’s as close to perfect as it can be (For me).
However, since the Steam Gamepad is so customizable, anyone can change the profile under the steam community profile page; or make your own template however you want!
One catch.
Must maintain Steam in Big Screen Mode (Or TV Mode) to read the community profile and cannot let it close or switch to Desktop mode or it’ll crash your controller profile.