Unfortunately, I believe you failed to evaluate several of the best iPad keyboard candidates. Each of the products you reviewed are combo iPad/keyboard cases where the size of the keyboard is limited to the width of the iPad (in portrait mode.) For those accustomed to a full-size keyboard, especially those who shift back and forth on a regular basis, the cramped keyboards you’ve reviewed are simply not very satisfactory.
Far better choices, imo, are the Apple Wireless Keyboard, the Microsoft 5000 bluetooth portable keyboard (identical to the 6000 model), and the Logitech Tablet Keyboard for iPad. Each is a nearly full-size keyboard and sufficiently portable to be used with the iPad and carried in a small messenger bag.