ive had 2 WILD now both i felt SP, i wouldnt say it is important to feel SP, if i had a choice i would i would choose to feel it though, i see it as a kind of heads up that your about to enter your dream n thats where i think to myself "dont forget to RC" SP is a good feeling though, say if i fall asleep with one hand lying above my head, during my dream i can use both my arms but still feel like one arm is above my head and i can move it!