From what I've heard, the other mulan series was a awful attempt of the adaptation of the legend. But then again I've never seen it so don't hold me on what I"m saying. I've just heard people say that.
Now for Anita's version, I've personally seen that, and I've got to say that it's an awesome series. My younger sister likes it, my parents, me, it's a series for the whole family. Definately one of the best series, you'll ever see.
From what I understand, the other series is a TVB series, therefore, you're more likely to see it if you are a fan of TVB or you watch cantonese series because Anita's adaptation of mulan is in mandarin.