With lack of tactility, the traditional on-screen keyboard on smartphones relies on touch-enabled display. However, the display also serves as a frame of reference for the position of keys. The keys also offer consistent size and linear placement.

Meanwhile, the ergonomic placement of the keys on the one-handed keyboard is certainly usable with a single hand, but it may take the user considerable amount of effort and time to learn the complex positioning of each keys unless haptic feedback is present.

In the keyboard design used on Microsoft Windows Phone, the frame of reference, uniform size and linear positioning is lost. While the keyboard is optimized for the optimal and uniform distance between the user's thumb and keys, the learning curve will be quite high for most users. Just as a tiny fraction of users use specialized keyboards or keyboard layouts for the purpose of maximizing productivity, ergonomics and utility for specific uses, Microsoft's take on on-screen keyboard is not designed for the mass audience.

In the end, there is a place for a keyboard like this. But not for the mass audience. Standardization will always triumph in the end...