Even better than this Logitech keyboard is the Perixx PERIBOARD-805L W. http://perixx.com/en/products/perixx-pro-4.html
This is a folding full-sized key bluetooth keyboard. It has REAL keys. They have great key travel and feel. I can rapidly touch type with it. It folds to the size of an iPhone 6 Plus. You can keep it in your pocket. It lasts months on a charge.
It is far better than the Logitech Keyboard described in this article. And at $29.95 it is cheaper too.