We actually did the opposite. I went from DirecTV to Dish, and we liked the quality of Dish best. It was noticable better. It is possible that either your Dish install (or my DirecTV install) were not ideal. Even when we first got Dish, we found out months later that the installer did a shoddy job. We had it done right and it was even better. I know a lot of people in the Des Moines area that went from DirecTV to Dish and like it. Some like the channel line-up packages better, or the price, whatever. I would pick either over cable TV and their expensive costs.
As for the Dish DVR, they keep updating the software about every 6 months, and we get new features, etc. Not sure about the Tivo piece.