I take seroquel - went from 200 mg to 300, now I'm at 400 mg.
It does knock me out, and at first I was very groggy in the morning and had a hard time waking up. But after a while my body seemed to adjust to it (as the doctors told me would happen) and now I don't have as much trouble waking up.
I hope you find that is your experience too, because seroquel is great for sleep and for me it is really nice to be able to sleep and not be plagued by nightmares and wakefulness. Give it a few days.......
good luck to you!