Last year, Lenovo surprised us with a novel concept. What if there was a laptop the size of a tablet with a touch-sensitive surface in place of a keyboard? That notion birthed the Yoga Book, a tablet-digitizer hybrid that had a 10-inch display on one side and a smooth, flat surface facing it. Long story short, we were excited about the premise, but ultimately disappointed by the terrible typing experience on what the company called its Halo keyboard.