Check the laws in your state on windshield replacement as they do vary. Some states require insurance companies to cover the cost of a new windshield, others do not. The states that require insurance to pick up the tab usually are much more strict on replacement once a crack appears.
Out here in Idaho, the transportation department makes spending any extra coin on windshields a ridiculous endeavor. In winter, roads are treated with sand (always with a large side-order of small rocks) rather than salt. In summer, the same roads are re-paved using a process called "chip-sealing" whereby they coat the surface with a gratuitous layer of small rocks loosely applied over the existing asphalt. The rocks only adhere to the surface after traffic has driven them into the asphalt. If you can get through a single year without a crack on your windshield, you probably were driving a different vehicle.
Moral of the story: if you have to replace your windshield with any regularity and/or out of your pocket, save your $ and get the standard glass.