Hi, this is a question I am most interested in as well. I haven't seen it answered yet.
In my personal case I have no doubt that it feels much better and stronger to trace the meridian DOWN. I do the microcosmic orbit (MCO) and it works very well for me. It may be a case of whether your energy flow has "shifted" somehow and/or your MCO is open. If it is then maybe it is better to run it downwards, if it isn't maybe upwards, just like you said it was shown by Yayama.
I also saw Donna's dvds and I highly respect her and so got puzzled...but, at least in my case, the taoist methods and anatomical framework (the dan tiens, mco, etc.) works better.
