Both satellite service providers have pretty much the same content and are pretty close in price once promotions timeout, we have had both and have switched back and forth a few times. We do a lot of camping where we often find obstructions to the southern sky and have found that a dish mounted on a tripod works best for us. We carry 150' of coax although it's rare we have to use that much to acquire a satisfactory signal.
We have HD at home and choose to go this route when RVing, not an issue as these HD dishes are readily available and take the same amount of time to point as an SD dish if you are familiar with the process. Since this method allows acquisition of all satellites at the same time we can watch different HD channels on different HDTVs within our rig without issue. Dish HD channels can be acquired by some portable/dome automatic sat finders, but none can get Directv HD content which requires an automated roof-mounted dish system.