In Geowriting: A Guide to Writing, Editing, and Printing in Earth Science, Robert Bates amusingly notes that “unique, like pregnant and dead, is an absolute: it cannot be more or less.” “Unique” means “being the only one of its kind”; “perfect” means “without flaw.” Professors reading of “a unique insight” or “a perfect software package” could correctly challenge these absolutes—i.e., the insight would certainly parallel others, and the software package could certainly be improved. By definition, uniqueness and perfection are so rare in scientific contexts that the concepts are best avoided in formal writing. And if you dare to refer to something as “perfectly unique,” keep an aspirin handy for your professor.