I'm looking for a word that describes people who have high standards for themselves and others and strive to achieve them, but don't expect absolute perfection. They are satisfied with realistic results. As in
Being a ________ [perfectionist], John spends a great deal of time ensuring the quality of work is above reproach.
I like "perfectionist", but it's too closely associated with words like "persnickety", "hypercritical", "nitpicky", "punctilious", "anal", "pedantic", etc.
I'm finding words like "meticulous", "rigorous", "conscientious", and "thorough", but none of these really fit quite right.