If you can get used to just using the two touchpads for everything then you can get the most out of the Steam Controller and no other controller compares.

For FPS games for example you can bind the left touchpad to left joystick, make the outer ring toggle the left click to 'run' then use the touchpad click to activate something else like dodge (B)

The right touchpad can function as mouse for look, but also on touch activate gyro as mouse to help with accuracy, then right click can be melee or even configure a 4 button pad so you have more options.

Then you have the back buttons and the 4 shoulder buttons all at your finger tips and you don't need to move your hands.

I like the touchpad for platformers too, completed Hollow Knight with just the touchpads