The new iPad offers 4G LTE, which offers great promise. But before you spend the extra $130 (plus monthly fees) for the LTE model, take a long look at the Verizon and AT&T coverage maps. When I did, it was clear to me that Verizon was the way to go, even though I have my family's cellphones on AT&T. AT&T simply doesn't have the 4G LTE coverage I need in my home and surrounding area. The benefit to having both providers is I should always be able to get online, either with my iPhone or new iPad!
Here are the links to AT&T and Verizon. Make sure you are looking at 4G LTE.