Someone else's two cents...Ambian knocks me out RIGHT AWAY! YAY. BUT...I've found, and others I have spoken to say the same thing. They (we) go to sleep right away, but the effects aren't a full night of sleep. In most cases, 3-4 hours! Which defeats your purpose. I've tried valium, which works sometimes if you're sleepy. Otherwise it just relaxes you a good bit.
The thing I've found to work the best, with no side effects nor "drunk" feeling when you wake up? A cheap OTC Sominex. Works wonders for me.