I had the old Prime Star way back in the day, they were bought out by Directv and I've had them for 12 years or more now. Is it perfect? No, I wish I could get rid of some channels and add a couple that I would actually watch, and I'm not talking HBO stuff either. But, the customer service has always been excellant and my neighbor who switched to TWC, switched back after a month of pain with those guys! Not sure about Dish, I've heard it's fine and I've heard it wasn't and they switched back to Directv.
I'd say try it!