Since there are many negative reviews of this medicine on UrbanDictionary I would like to add my opinion.
I take a relatively low dose of 150-300 mg at 8pm every night to help me fall a sleep at 10pm and to help me sleep a full night.
This medicine has helped me A LOT during the 2 years that I've taken 150-300 mgs/night because I can now live without any sleep issues. I do not experience any downsides, I am not sleepy during the day, I have no problems concentrating or focusing on the tasks at hand and I wake up well rested and ready for the day after 6-9 hours of sleep depending on when my alarm goes off.
I too have experienced the downsides of Seroquel but only when I was taking 600mgs or more. My symptoms at that time was dizzyness, somnolence, fainting, tachycardia and irregular heartbeat. You should be aware that this could happen when taking Seroquel!
As every other drug/medicine this should be used with caution and you should be aware of what your body is experiencing but this is not a horrible drug, it works for many people (including me when I got the dosage right) and PLEASE, don't trust just one review of this medicine, talk to your physician, to others who have had experience taking Seroquel and it could end up helping you.