I passionately hate seroquel but find that it's very effective to stop a psychotic episode in it's tracks.
I was on 600mg at night a couple weeks after going psychotic. I experienced several negative side effects including arrthymia, blacking out, feeling like a zombie and extreme hunger. All I wanted to do while taking it was lay around and eat chocolate ice cream, granted that's all I want to do when I'm not taking it! I also blacked out after taking it a couple times. I was on my way to the freezer to grab some ice cream and feel and hit my head.
Be cautious about walking around after you take a dose so you don't have the same thing happen.