I tried schiff melatonin ultra, they sucked really bad I sleep 3-4 hours with them. From what I could see they are not time released plus they have a bunch of other ingredients I dont want like gaba, L-theanine, valieran...
I have tried circadin which is pharmacy quality and they really make the difference but they are just too expensive at the moment. About $30 bucks every 7 days
http://www.circadin.com/