Directv uses more satellites for its HD programming.
Some old KVH tracking dishes are not capable of receiving HD.
Many of the newer RV automatic dishes will not pick up all 4 of Directv HD satellites. (Limiting HD programming).
All of Dish network HD programming is sent on three satellites that can be picked up by most of the newer tracking RV top satellite dishes( KVH, & Winegard).
I just switched from Directv to Dish network after finding that my old KVH LM would not upgrade to any HD and many of the newer tracking dishes only offer limited Directv HD programming.
Winegard a good price and were first to respond with excellent text support.
Dish has been very helpful in the change over.
Other than the above both networks offer similar products and values.
I had Directv for 8 yrs the only complaint was losing local (Chicago) channels on the satellite when out of Directv local signal area. It was strange how that worked. I would get Chicago channels al over Lower Michigan,IN,Il, and loose them in Upper MI,MN & WI.When I applied for exemption I was always turned down without explanation.
I really don't have any answers just a little lame information.
I ended up with:
Winegard Roadtrip SD (Stationary Tracking dish)
Vizio Flatscreen