My surgery was at 7:00 a.m, and was out of surgery at about 2:30 - 3:00 p.m. (only took that long because they found out during surgery about my BAV, and impromptu installed a mechanical valve). I have a slight recollection of being extubated, mainly being held up by nurses, the tube coming out, and falling back into a laying position (whatever time that was). Another slight recollection I have was I came to for about 5 seconds, saw my mother sitting in the room on her phone (we joke about her playing candy crush, haha) and blacked back out (no idea what time that was).
I started to become coherent and responsive at about 2 am the next morning, as I asked for 1) a glass of water, and 2) what time it was.
I didn't really experience any hallucinations, the only side effect I remember was quite arguably the WORST dry mouth I've ever experienced. Instead of cottonmouth, I called it Sahara mouth.
In short, judging by the answers I'd assume it really depends on a combination of the patient, anesthesiologist, and sedatives. As they affect everybody differently.
Hope this helped!
-Koz