Generally you want to use NS if you're in melee range and your target is going to get heals before you kill them.
Without any procs or Razorice or anything, on a target dummy I do:
NS: 24109 antiheal plus 10-15kish* strike
PVPP and Resilience would keep these numbers in equal proportion.
* 10127-14972 paperdoll, NS is 150% weapon damage, dummy takes about 65%, so dummy takes slightly less than paperdoll. Plate+shield, mail+shield, and plate+2H would all take a little less than dummy; mail, leather and cloth would take more.