From the Sats2Go website. We use Sats2Go in Houston for our satellite work and upgrades. He would know the answer.
The Selection of Open Faced vs. Domed Systems:
The choice is yours! Open faced antennas, will provide you with a greater reception opportunity for programming in DishNetwork, Bell Express Vu or DirecTV programming. If you currently have DishNetwork Dish500 or Super Dish, Dish HD or DirecTV HD satellite programming, this requires an antenna to have multiple satellite LNB's for your programming to come in simultaneously, you can only achieve this with an open faced antenna. If you use a domed antenna with this type of programming package, the antenna has to "toggle" between the two different satellite locations and can only truly support one (1) satellite receiver for proper functionality. If you select DishNetwork lower end programming package or DirecTV non HD programming packages, the domed antenna will serve you well for single, DVR or multiple receiver applications. With the open faced antennas, you do have to remember when breaking camp and preparing to move the RV that the antenna is stowed, whereas with the domed antenna, you can just drive away.