Cannabis completely stops me from dreaming and gives me a slightly less satisfying sleep (compared to sober nights), kind of similar to general anaesthetic. On the other hand, cannabis really helps me take the edge off of any stress and anxiety that builds up over a day, which can keep me awake and even give me nightmares. So really it's a balance. The golden rule with all regular narcotic use is to take as little as possible to feel satisfied. Personally, I have started vaping (e-liquid and dry herb) every night and occasionally during the day. With vaping, dosage is lower and extraction is much purer. About once a week I feel like getting major blackout, red-eye stoned so I have a fat blunt or 3. But that definitely should not be the norm in my opinion. Cannabis culture has a long way to go in regards to working out dosing, units etc.