I have also experienced some long download delays recently. However, I think you all need to exercise patience, and take into consideration how much Apple's servers are taxed during the first few days when a new OS is released. Unless you have some pressing need to install Sierra right away -- perhaps because you are a developer -- wait a few more days until the demand dies down a bit, and then try again. Or else try downloading at an odd hour of the day -- such as late at night -- when other people in your particular area might be asleep. There really isn't much else that you can do.
