THE ZOHAR, volume 1, is reviewed by Jacob Neusner in the Jerusalem Post. Excerpt:

The Zohar, the apex of Jewish mysticism, has been dismissed by modern Jewish scholars, represented by German-Jewish historian Heinrich Graetz as nonsense, and rehabilitated by Israeli and European experts on Judaism as substantive.

Here the pendulum swings back: the Zohar is at best impenetrable, at worst nonsense. This translation proves that even those who know the text best cannot make it accessible, either in translation or in explanation.

That gives you the flavor of the review. I haven't read the Zohar in Aramaic or seen Matt's translation, so I can't comment on most of Neusner's criticisms. But I don't understand this one:

First, the text that is translated does not exist outside of Matt's own study: "If I could have located a complete, reliable manuscript... this would have provided a starting point." He ignores the standard printed text, but has composed what he calls "a critical text," which is "based on a selection and evaluation of the manuscript readings."

That means his translation correlates only loosely with the available printed versions.

It's standard practice to produce a critical, eclectic text, based on evalution of the manuscripts, when working on an ancient document. Often earlier printed texts of ancient documents are based on late and corrupt manuscripts and reflect the original text very imperfectly. If Neusner has criticisms of the specific critical text Matt has reconstructed, fine, and tell us more, but the concept of a critical text isn't new or controversial. It's the proper way to proceed if the objective is to produce a translation of (the best approximation of) the text that Moses de Leon wrote.