I was prescribed Seroquel for insomnia. I am Bipolar Type II subjected to extreme stress on a daily basis which causes me chronic insomnia, among other things. Apparently I am very sensitive to it. The first night I took one pill and it knocked me out for about thirteen hours. It hit me REALLY hard and it scared me. But, I was fine. I also experienced an EXTREME hangover in the morning that kept me in bed even longer. And that was from only 25mg. But, I did get a good night's sleep. On the other hand, I have really long, fast-paced workdays and have to commute about 500 miles a week, so I couldn't afford to have the hangovers. Therefore, I decided to try something different, because the nights I would experience the insomnia were the nights when I knew I had a really rough day ahead the next day and couldn't afford to be groggy.
I don't know what you take it for, and everyone is different. For me, personally, it wasn't the right fit. But my reasons were also unique to me. But aside from the groggyness, the medication was fine.
Hope this helps.