It is a matter of taste. I could not smoke the same pipe for the whole day, because I feel it looses taste after the second smoke. I carry a bag for 4 pipes, if I leave for a few days, so I can smoke up to 8 pipes at a given day, but mostly this is not possible anyways, as you cannot smoke in many places anymore. I have pipes, which are 30 years in my possession, which show no signs of becoming sour, so why stress them. I know smokers, who do rotate a few pipes only and they have exchange them every few years, but it is not that easy to find great smoking pipes, so I'd rather keep what I have in good shape.