I normally do a 3 week primary, then bottle. If I'm dry hopping, I'll put them in the last 5-7 days before bottling.
A secondary would have to change the laws of physics to make your beer more clear than the same time in primary. Gravity works the same everywhere, all the time. Commercial brewers use secondaries, called "bright tanks," partly because temperature management issues and pressure and on the yeast is much greater on a commercial scale than what we have to deal with. But largely it's because of the economic need to keep the fermenters fermenting. A commercial fermenter is a very specialized piece of equipment, a bright tank, not so much. Moving the beer to the bright tank for lagering keeps the fermenter(s) making money. Most of them filter their beer for clarity anyway.