Mentor is relatively new compared to Zen, with
about the same PE and BC. Zen has a higher IC.
Sims show very little difference in the results of
using either count.
IMHO the symmetry of the Mentor tags is appealing.
Mr. Renzey has done a fine job presenting his work
on Mentor. Counters seeking additional EV should
consider either Mentor or Zen, over level 1 counts.
Additional EV can help offset 6D/8D liabilities, if shoes
mainly comprise your local games. They can, however,
be more difficult to learn and use.
Know your limitations. Simple is sometimes better.
BJinNJ