I tend to use pin feet more often than sneak/rapid shot to open if I know I can kill them without needing a second stun. Snipe/avulsion does most of the damage anyway. I just find sneak/RS takes too long sometimes when I'm farming/grinding, whereas pin feet casts immediately. Everything feels faster with it. I use sneak/RS mostly when I'm doing a quest to kill a boss and I need to be able to stun him as often as possible. Or if my pin feet is on CD when I take on the next mob