One other cool SD feature, is if you have a game you can’t remap the keys for and isn’t gamepad friendly like old RPGs that need the number keys for spells etc, you can create a radial menu that will overlay a custom designed menu that you can map to one of your trackpads.

Yessssss, Virtual menus are the unsung hero of Steam Input. They make so many games playable that aren’t on any other handheld.

Beyond that, I’d say… Desktop mode is a awesome feature, because it means you can do damn near anything you could do on any other computer.