Usually the sites are priced by amenities--preferred is closer to things and has elec/water/sewer/and cable. Full hook-up may not be quite so close to things and does not have cable and is usually a little cheaper than preferred. Partial hook-up sites do not have sewer or cable and are usually the cheapest. Tents can camp anywhere and there are only two loops that are partial hook-up sites--1500 is in the middle of the action and 2000 is a larger loop farther out. Hope this helps!
Partial Hook-ups (for tents and pop-ups) are less than the full hook-ups. But as the previous poster said, tents are welcome to use the full hook-up sites but you will pay the full hook-up rate. Here's a list of the sites with their rates: http://www.allears.net/acc/faq_fw.htm