Hank,
I'll add a comment although I'm not sure it contributes much to your question. I also have the Winegard Road Trip P4 dome. Although I picked my RV up in February, I didn't attempt to set up the satellite until a couple months ago. We are long-time (satisfied) Direct TV customers with our home system, so I didn't really consider using Dish Network in the RV. I decided to get a dedicated receiver/recorder for the RV so I wouldn't disrupt the home system when I'm on the road, and ordered a Direct TV HR-24 from Winegard. The up front cost was $200---but after that the only addition to our bill is the monthly receiver lease of $7. Interestingly, I do not have SWM equipment in my installation (although I think Winegard indicates you are supposed to use the SWM adapter for the P4 antenna and that particular receiver)--but my installation works perfectly. It's true that the setup does not provide HD TV, but I have to say that the picture looks absolutely perfect on the 32" Samsung in the RV.
After looking at the links that Don posted on the Dish deals, I think they look very good--considering the nominal prices, intermittent pricing on the service depending on use, and availability of HD. If I didn't already have the DTV home subscription to tap in to, I think the Dish deal would merit careful consideration.
All the best, Mike