Have only tried cinnamon sticks in one mead, a cyser, so far.......when bottled, it tasted pretty darned good, but as the bottles aged even further, the "cinnamonyness" faded over time to a more woody/earthy flavor ... not bad, but not quite the cinnamon flavor I was looking for.....possibly because the so-called cinnamon sticks i bought were likely actually cassia, not "true" cinnamon, dunno....I think I threw a couple in primary (possibly a waste of time/sticks) and perhaps 3 to 5 more in secondary for 5 gallons......maybe cinnamon flavor is like hop flavor and diminishes over time, dunno that either. I have a gallon of oaked bochet cyser that has FINALLY cleared (used supposedly fresh pressed cider from a local farmer's market, was cloudy forever), am contemplating doing some sticks, but may ramp it up to a higher amount and hopefully it'll be flavorful for the long haul.....stiill contemplating this addition, as I was underwhelmed by my first try after a year in bottles....tastes fine (my future son in law loves it, but he wishes it was sparkling....heh), but....I want more cinnamon flavor!!!