Depending on the strain, if you harvest earlier with lots of cloudy trichomes and less amber, you'll get more of a "head" high, with more amber you'll get more of a body, couch lock (good for watching GoT!) high. And if you wait TOO long, yer tucked! It's a matter of personal preference, I like the head high as my wife and I play Carcassonne, a strategic board game, when we're blasted. Always fun to come up with a great move and than forget it when it's your turn.