I started on 600mg so not too far off really. It wasn't too bad, I didn't have any sicky feeling in my stomach like some of the others had caused. I did however sleep like a log for quite sometime which is unusual for me as i barely sleep normally. The effect would follow on into day time, but you get used to it after a week or so. I'm currently on the prolonged release ones but changing to the normal ones next week.
Like you they do work ok for my negative symptoms. Hallucinations, both auditory and visual still persistent. Since being on them I have put on a little weight.