Yeah I tried the first example (A-E) on their memorize site and was blown away by how poorly thought out the whole thing was. It asked for the answer in dotsies and all that came to mind was "... uh, a dot somewhere around this region? -click- oh nope, it was up here further. How mind-numbingly interesting."
If you've got a better mapping in mind, post it. It would be interesting to see.
Many things must be taken into account beyond just where the dots seem like they should go on the letters. However, there's a decent enough correlation on enough of the letters that I suggest it would be pretty easy for you to remember them. For example, A, C, F, H, I, K, O, P, R, S.
I'm just not convinced that single dots work well without gridlines showing their relative position on the page. Maybe it needs a better demonstration, or maybe I'm just not getting it. I don't want to take away from your accomplishment, I can tell a lot of thought went into it. But, like Dvorak, it might be better, but is it better enough to put in the effort to switch?