Totally agree, spaced repetion has its role but has huge limitations. The limit of most programs is that it has you learn in a unidirectional manner, so very few memory pathways are formed and they are easily lost/degraded with time. As an post states, the flashcards didn't stay, but the characters you learned while in Japan stuck. I submit that part of that is that this material was presented to you in several ways (signs, books, TV, etc), rather than just flipping a card over and over. I've started using Memorang instead of anki, as it allows me to retain information in the long term, as it has multiple ways to approach/learn the same info.
Add the fact that it's free to generate your own content which is perfect for me (speaking as a medical stuff with thousands of facts to not only memorize but apply)