One thing I do not understand is when Chasidim insist on nusachim. Whole Chasidic thing started as a radical departure from Ashkenaz with various justifications.
Another thing we do not appreciate is where the variety is: all Ashkenaz come from a narrow set of people, both genetically and as nusach and minhag goes, while “Sepharad” represents a multitude of tradition – real Spanish and all other countries where Jews lived for a millennium and more.