When you want to describe a difference or a separation that is subtle, there are many synonyms for the phrase "nice distinction". Some of these include the phrase "fine delineation", the term "subtle differentiation", the expression "delicate demarcation", or the words "exquisite separation". Other similar phrases and words that can be used instead of "nice distinction" include "precise contrast", "nuanced divergence", or "delightful discrimination". All of these phrases evoke a sense of precision, elegance, and sensitivity in the words that are chosen to describe the separation of two ideas or concepts.