it is the most appealing and romantic of the complications. I imagine only a tiny percentage of watch enthusiasts follow and use the moonphase function for a practical purpose in their every day lives. Yet, it adds true artistry (especially the enameled versions pre 3970) and extreme desirability to the dial. The fact that Patek can make it so so extraordinarily accurate is an amazing feat that I very much appreciate. So bottom line, while for me to it is the least practical complication I love having watches with a moonphase.