Compared to translators such as Harvey and Barks, Arberry is the superior translator. Perhaps it takes a certain amount and kind of understanding to do a good translating, or perhaps it takes knowledge and literary-language skill, or perhaps it takes all of these. There have always been vast problems choosing with translation to get in Middle Eastern and Far Eastern studies; my experience with Far Eastern studies/translations is that the translator really has to be humble and present with the original poet. In this case, the translator must let Rumi speak, and Arberry does that better than many other common translators.