I've had both, but currently have Direct TV. I found at home with a permanent dish set up there wasn't much difference between the two,although it seemed that I would lose the signal more often (even though the dish couldn't be aimed any better) in bad weather, with Dish network.
To me the big difference is while camping and setting up a portable dish. Direct TV at least for me is so much easier than Dish network. I found it impossible without a signal meter to find Dish network's satellites. Even with the meter it was always a hassle. With Direct TV I just get my compass, aim the dish, and normally I can quickly find the satellite.
For years I've been meaning to get a sat. dish mounted on my RV, but that hasn't happened yet. :)