Satellite internet is pretty awful compared to cable or dsl, unless its your only option, then its pretty good. Its better than it was years ago but people used to wire based broadband will probably be disappointed in both the cost and the performance. Last time I checked you either had to ante up about $500 up front for the equipment and then a pretty big (bigger than cable) monthly fee, or have a humongous monthly fee with no upfront cost, and a long commitment for service.
Comcast in most areas gives you a break on internet cost if you have cable tv. The little secret is that in most areas, if you add the $8-10 super basic CATV package, they'll give you a $10-12 discount. And then at least you've got your local broadcast channels on each cable outlet sort of for free.
Comcasts "digital voice" is VOIP based and my experience with that was poor as a primary line. Too many things to go wrong between your house and the phone company, then all the phone company problems to boot.
Really, your cable picture quality experience will vary based on the age and quality of your neighborhood cable plant and the run to your house + whats inside the house, unless you get digital cable. Even with DC, your first 99 channels will still be analog so unless there are digital duplicates in the >99 channel range, your PQ wont improve.
In general my comcast experiences have been lousy. Mixed picture quality, occasional outages, poor customer service, and high prices. My directv experiences have been decent. Good PQ, very few outages, and fair to good customer service.
The DVR thing is another matter altogether. Tivo and Directv pretty much hate each others guts. I think the odds of that relationship improving are about .02%. You cant buy a true "tivo" for directv anymore unless you get a used one, and then they'll charge you extra activation fees to get it going and if it breaks, you're SOL. The directv dvr runs different software and in their efforts to avoid tivo's thick book of patents, the product seems a bit disjointed and lacks a few things that I like. We just replaced our directv tivo's with the directv dvrs. Long learning curve. The directv remotes are lousy compared to the tivo remotes, but they can operate through RF so you dont need line of sight to the unit. The directv dvr is faster to operate, but there are no suggestions and wishlist type functionality is very limited. The directv dvr has a hard time figuring out the difference between first run shows and reruns, so you get a lot of reruns on your first run season passes. Seems to me after a week of use that the directv dvr is more glitchy and somewhat more problematic than the old series/x tivo's and directivo's.
Comcast has patched up their relationship with tivo and is rolling out tivo software on their dvr boxes. Sort of. Turns out that its more like tivo menus on top of the old comcast software, with some of the tivo patented features rolled in.
I've got a couple of friends who, like me, have gone through comcast, dish network and directv. Nobody liked Dish network. The PQ stinks, the customer service is the bottom of the bucket, and their dvr is awful. Most seem to think the HD offerings on directv are better than the comcast offerings in selection and quality. Most seem to like the directv dvr more than the pre-tivo comcast unit.
I've also always found a place on the house to hide the dish where its not particularly visible.
Directv has a pretty good deal running right now if you want plenty of channels. $63 a month for two months for their 'platinum' which has all the channels including all the premium movie channels, then $80-something a month for ten months. Free dish, free HD receiver or DVR. If you sign up through fatwallet you can get a $35 fatcash rebate. Sign up for debit payment ("go green") and get another $20 credit. Use the "refer a friend" program if you have a friend with directv and you'll both get a $50 billing credit. Buy a new HD tv and sign up for directv through comcast and you'll get a $150 rebate.