I have a wifi model and I am very happy with the device, in general, but I am wondering how the 3G speed is around the U.S.? I travel a lot and I know for a fact that there is significant differences with my iPhone on the 3G networks. In some cities, usually during large conferences with tens of thousands of people boggling down the towers I have experienced 3G become unusable. For some reason this really is a big problem in Las Vegas at the Mandalay Bay. Anyway, in general how is your experience on the 3G iPad?