How Important is Double Pane Windows? (Precept 3UL & others)

Most important window the windhield is the same regardless

roof, floor and back of MH is same regardless of window type.

The windows are such a small part of heat transfer that it is not that important. Yes dual pane will provide more insulation but when you look at totality of all surface areas it will not matter that much.

Exception is those who live up north and hate condensation on windows

Much more important in Arizona would be is your windshield pointed at the sun in hot weather - that is a BIG deal