I don’t think the positioning will feel too different from the Deck honestly. Your hands are going to be closer together holding the controller and thus rotated more inward. It looks like Valve rotated the grips and stick/button/trackpad triangles to match this angle, hence the lower sticks and tilted trackpads. The ergonomics on the Deck, original Steam Controller, Index controllers, and Index headset have all been great, so I trust them here.