In my few exposures to monastic prayer (at Conyers, St. Meinrad and Gethsemane), I have to say that Compline has affected me the most deeply. I'm too tired in the morning, still distracted at Vespers, but finally relaxed in the evening. What is always most memorable is that final offering of the Salve Regina, the gently plaintive words echoing through a darkened chapel.
If you ever wonder why you're Catholic, go to Compline. You'll remember.