I'm very happy with DirecTV and have one of their discontinued Tivo DVR but when I get HD I may switch back to Comcast cable so that I can have a real Tivo instead of the DirecTV DVR. I've heard nothing good about the DirecTV DVR and DirecTV ended their agreement with Tivo a few years ago so their new HD programing does not work with Tivo. Comcast announced this year that they were going with Tivo and you can already get a cable card for your Tivo.
My neighbor had both and DirecTV seemed much better then Dish as far as interface but I'm not really sure which had better programing since he only used the Dish for porn.
Here are the DirecTV forums
http://forums.directv.com/pe/action/...ardID=10100106