Although these two systems are essentially the same thing, many people seemto disagree on which one is more powerful. Granted, the difference in ev is not highly noticable, but I am interested in everyone's opinion on the 2 counts.
On one of Snyder's sites: http://rge21.com/lib/hundred.htm, he says the zen is more powerful than ho2, but ho2 is simpler. The ho2 count is simpler, but I would think its need for ace adjustment would actually make it more difficult than zen.
And then there are sites like: http://www.conjelco.com/faq/bj.html#B19 with tables that show pe, be, and ic, where ho2 seems to outperform zen slightly in all 3 catagories.