It wasn't the first time I've bough I Microsoft mouse. I bought one back about a decade or so ago when another Logitech mouse died. It suffered the same fate as the Microsoft touch mouse. It was returned to the store and exchanged for another Logitech - for exactly the same reason.
Neither was acceptable for my workflow. Unsurprisingly, I spend a meaningful amount of time using CAD/BIM software. The touch mouse zoomed in when I adjusted my grip ("drawing" with a mouse largely involves holding it). There was no way to program the gestures. Likewise, the earlier Microsoft mouse had lots of buttons, but no way to program the middle button as a middle button - as an early "many button" mouse, the middle button had some dedicated function and I had about a decade of muscle memory and projects to push out the door.
The author is experiencing the same thing. The new device isn't tailored to his workflow. It probably isn't reasonable to expect it to be. It's competitors aren't; most people don't have a similar workflow; and it's still version one of the software (Word for RT).
This doesn't excuse the devices performance. But it also puts the author's experience in perspective. Right now, he's somewhat of an edge use case.