[xiaoma]

Honestly, once you know either pinyin or zhuyin, learning the other is trivial. It took under a day for me to get it 95% down and then with some regular usage it was done. But one effect was I found I had a much easier time keeping sounds straight than my fellow learners who often confused sounds that had less straight-forward mappings in the system they learned.

Learning IPA on top is an extreme but still useful third point of attack and again, it's trivial compared to the difficulty of actually learning to hear the sounds clearly. It must have been a year before I realized how different the d in pinyin and the d in English were.