This guy will have to wait for his younger brother.
It was available to buy starting noon local time. I refreshed the page until the buy option became available, but kept getting an error when submitting payment. Waited about half an hour and now it’s sold out. Ni modo I guess.
It has trackpad which allow you to play KB+mouse games very fluidly. Also they can be used to add radial or grid buttons to any game.
It has TMR sticks which means no drift and less power consumption.
It has a gyro.
It has 4 back buttons.
It’s fully compatible with steam Input so you can do crazy mappings of every single input.
It has capacitive sensors on the thumb sticks and handles so you can use that as input or modifiers.
It uses a dedicated dongle that has a latency comparable with plugged device according to some tests.
It also connects via cable or Bluetooth.
It’s very reparable friendly and Valve will be offering replacement parts.