I think it depends on the individual. Lots of people have fairly good technique naturally (especially if they are not overweight). I think concentrating on relaxing, been up on your toes and falling forward are worthwhile. I'm not sure you need to put tons of work into this though - it's really just running how your body is designed to after all. Like I said I think the whole thing goes out the window if you're wearing boots and carrying weights.
Dave I wonder whether technical improvements cause greater efficiency in running or cycling? My instinct is that getting as close to a perfect circle in your cycling stroke will cause a massive increase in speed - however I don't cycle so this may be rubbish.
So I think POSE/CHI/running well are valuable if used in conjunction with running training. I don't think it's enough (in Allen's case) on it's own. And like I said add webbing, pack, rifle and a helmet and try to run POSE and it's just not happening for the majority of people.