I'm specced for the longer SnD, and glyphed as well(combat spec). If I SnD with just 1 cp it gives me just over 20 secs of the buff. It seems unproductive to use SnD with anything more, since the 1cp/20secs is definitely the highest sec/cp spent rate. That doesnt take into account the energy required to cast SnD, however.
So my rogue friends, what is the ideal number of # to SnD with for max dps?