Comcast v Dish TV

(I won't use DirectTV because it's owned by Rupert Murdoch, for personal political reasons).

I'd like to ask for suggestions on choosing Comast Digital versus Dish.

I've had Comast Digital for years. It's about $90/month. It meets my basic needs for shows, and has benefits I could use such as 'on demand'.


Dish TV seems to have a similar selection, for less money, and a nice DVR option.

With basic and extended cable and HBO/Showtime Comcast about $90/month.

Now the questions:

What should I conisder that I might not be aware of?

I don't use HDTV today but probably will soon and want to plan for it.
I'd like to get a DVR. The Dish TV seems to have good options for a DVR; the Comcast one is reportedly missing a feature I want, the option to watch one show and record another at the same time.

What will I miss if I switch to Dish? What will I gain?

How does the picture quality compare? Are there technology compatibilities to worry about? (For example, hooking up a PC to the signal).

Thanks.