Ambien, at least, is not addictive, and is much more effective at inducing sleep than any sort of addictive sedative medications.
This isn't to say it's not dangerous, since if you take ambien and forget to go to sleep, you'll be acting like this asshole (NSFW):
http://www.youtube.com/watch?v=J4z7mm4uEFM
If you live with someone, get them to hide your ambien and other prescriptions and especially your car keys; you'll drive off a fucking cliff on ambien. It's like drinking 20 bottles of wine in about 30 minutes, easily the most powerful sleeping pill there is.
The only real problem after acting like a retarded jackass if you forget to go to sleep is that, tolerance builds up hell of fast; first three days are 5 milligrams, fourth day is 15, fifth day is 30, etc. It'll drop fast, too, so my recommendation would be taking it only when you really need to get up the next morning.