One thing that has always bugged me about the "schools" of running is how the lean is characterized. Pose running, Chi running, etc., advocate a whole-body lean for running. While this may be a good idea, it is taken to an extreme when they say that the more you lean, the faster you will run.
This is patently false, as you can find some elite runners that have a slight lean and others that do not. So a lean is not a necessary condition for running fast.
However, I do think the idea has value. For us mortal runners, I think the lean is an excellent cue. When I focus on leaning, I tend to get my feet landing more under my hips. And that 's the real value of the lean, I believe: it can help get your body in better position and therefore lead to more efficient running.