At one point I had a prescription to both Ambien and Sonata at once, over a period of about 4 months I railed both to the fullest :D What's very, very odd about their action on me is that while I was given them for sleep, I never once had anything but the opposite effect. I would sit up for a good 2-4 hours after doing them and just trip face, wide awake. In fact, moreso than before I took them.
I found Sonata much more to my liking. Not only is it entirely painless where as Ambien feels like you just snorted Lye, but the feeling was much more enjoyable.
Ambien was more of a comatose feeling + hallucinations whereas Sonata was very euphoric, along with INSANE hallucinations and visual modulation.
At a dose above 20-30mg sonata anything I would stare at would move or react, ANY object. All the books on the bookshelf would leap in and out, up and down. My ceiling fan about 5ft away on the ceiling would slowly slide across the ceiling until it was directly above me. Not to mention a brightening and modulation in size/proportion of everything, very reminiscient of mushrooms.