The choice is relatively simple.
If you have a physical address and the ability to use a 3LNB antenna - go with Direct TV - the domes won't do HD on Direct.
If you don't have a physical address (S/B home or use a relative's address - i.e. you use a mailing service like Escapee's or South Dakota) go with Dish.
Direct offers distant network services
Dish does not - however without a S/B home/ address - you can change your 'service address' quickly and easily - allowing you to get the local channels anywhere. We've done that from New Mexico to Key West to Maine and back to Texas in the past year.
(Another note - when dealing with Dish - ALWAYS use the on-line chat - much faster, better and accurate than trying to make a phone call to a person. Did the service address change yesterday - took seven minutes from starting the on-line chat until the channels updated. Did have to reprogram the DVR for the new local channel for an ABC network program the wife loves.)