I did check that book out from the library and was disappointed that I couldn't really 'get' the whole walking on the balls of my feet. When I do that, it turns into running? How does that work?
Chances are you might not be leaning forward enough at your ankles. When done properly,
and IMO a pretty hard concept to put into action by most people, the movement is very fluid and never is there a time when both feet are off the ground thereby fulfilling the
RUNNING definition. As Dave mentions the stride is more like a shuffle with very short stride lengths and because the stride is short a very large base is needed before faster speeds result.
Most people will give up on Chi Walking because it just doesn't work for them but my bad knees forced me to find something that worked and since I was pain free and a thick headed individual I enjoyed the challenge.
Before I
found my own form to faster speeds the absolute coolest thing that would happen when I would start to walk would be the transition from just warm-up walking into C.W. mode. Getting into myself, feeling the shift in my hips, the smoothness in the stride, the attention to breathing and entire body feedback was and still is
awesome. Might sound corny but I really do get into myself and because of this I am able to train or race without the need of company or music. Heck, my longest bicycle ride of 201 miles in a day started at 1:30AM on Halloween 2010 and for all but 40 miles I was by myself and enjoying it.
If C.W. does not work for you, don't worry. The most import thing is to get out and enjoy the effort.
Good luck.