I'm on 350mg of Clozapine. I also drool like crazy while sleeping but atrovent spray kinda helps control that. I was on 450mg and then 475mg but I got a bad case of clozapine induced colitis and they bumped me back to 350mg. But I have a history of problems there so it might not affect you that way.
If you have ocd tendencies it can bring those out, thats why I'm on an antidepressant too.
I used to take it in the daytime as well but it was too sedating so it's only a night time dose now. I think the voices are quieter than they would be without it but I still hear them. I wish it would totally silence them.
Agree that it makes you sleep better though!
Just my personal experience, hope that helps.