Ĥida writes in the name of Arizal that prayer recited the Sephardic nusaĥ ascends through any of the twelve gates. Therefore, in his opinion, Ashkenazim may switch to the Sephardic nusaĥ (see Yabi’a Omer 6:10; Yeĥaveh Da’at 3:6). In contrast, Ĥasidim claim that their nusaĥ (called “Nusaĥ Sepharad” even though it was developed as the liturgy of Eastern European Ĥasidic communities and was not practiced in Sephardic communities) is superior. They maintain that the greatest Ĥasidim investigated and examined numerous versions of the liturgy based on kabbalistic meanings and halakhic considerations and and selected the best among them. The Yemenites, too, claim that their nusaĥ is most precise, for the Jews of Yemen, in all their years of exile, did not wander. Rather, in response to Arab persecution of Yemenite Jews, these communities intensified their dogged and meticulous preservation of their customs. Indeed, Yemenite Torah have been found to be closest in their precision to the Aleppo Codex, the standard of precision for the Torah text. Of course, those who pray in the Ashkenazic nusaĥ also assert that their custom is the most meticulous, transmitted from person to person as far back as Shimon Ha-Pekuli. Furthermore, the basis for Sephardic custom lies with the Amora’im and Ge’onim of Babylonia, whereas Ashkenazic custom originates with the Amora’im and Ge’onim of Eretz Yisrael, who were more proficient in aggada, esoteric wisdom, and liturgy. Incidentally, the reason for certain similarities between the Ashkenazic and the original Yemenite nusaĥ (Baladi), is that both were influenced by the Ge’onim of Eretz Yisrael.
In general, every rite has advantages, and it is not in our power to determine which one is superior. As states in Responsa Ĥatam Sofer (1:15), every nusaĥ is equal, and the fact that Arizal offered mystical interpretations of Nusaĥ Sephard is because he was accustomed to praying in that nusaĥ. Had he been accustomed to praying in the Ashkenazic Nusaĥ, he would have composed mystical kavanot for that rite.
Even if we were to know that a particular custom is more precise, it would still be proper for everyone to continue practicing their received customs, for continuing ancestral traditions is a strong basis for faith. Moreover, even less accurate rites certainly have specific points in their favor that we must be careful to preserve. Only after the Sanhedrin is established will we be able to institute a uniform nusaĥ, which will incorporate the benefits of each nusaĥ. Yet even then, there will be room for different emphases in supplementary prayers and distinct melodies, corresponding to the twelve gates; each community according to its ways.