"i take ambien, ambien cr and rotate to lunesta briefly when they build a tolerance. ambien is first rate though. they all have an odd effect of not drifting off - i blink and wake up in the morning. i&#039;m ok with that. ambien cr makes me a bit cranky if i wake early, like the cat waking me. otherwise they all work, and fast, like 30 minutes. i have a small amount of ambien cr left, which i think is the best but it&#039;s expensive. the others are generic, but work ok."