Let's look at this from MY point of view as we do BOTH installs.
Bottom line:
For customers that want about 120 channels worth on standard receivers, it's not much different between the two.
When you want less than 120 channels, you go with DISH for lower-priced digital packages.
When you want more than 120 channels, you can either go with DirecTV for maybe 25 more or 60 more with DISH.
If you want NFL Sunday Ticket, no question, you have to go with DirecTV.
If you want international, go with DISH as DirecTV has only a few exclusives and have a bad implementation policy of 72.5/95 dish + elliptical dish on an install. For those customers, they have to pay $150 for the 95 dish if for international programming AND $100 for the 6x8 switch which is very expensive to buy. BAD planing by DirecTV on that part and our customers suffered from that.
If you want HD, this is a toss-up. If you live in an area where you can get the networks in HD, then go with DirecTV. But if you don't want to pay the upfront cost of an HD receiver with DirecTV and can't get too many networks in HD, go with DISH. By the way, DISH is coming with LIL HD by this year for major markets. Don't ask me more on that or I'll get in trouble. On the same token, DirecTV is coming out with a 4-satellite dish and I don't think I'm supposed to reveal that either.
If you want DVR, this is also a toss-up. If you don't want to pay $99 upfront and get $50 back in a mail-in rebate, get the 522, 510, or the 625 from DISH. Otherwise, get the TiVo for its NBR and dual-tuner capability. However, the TiVo IS TOO SLOW FOR ITS GOODNESS. Why they'd make the darn thing so slow and implement a fix so late is beyond me. DirecTV is NOTORIOUS for releasing crucial fixes really late. DISH makes buggy software but it doesn't affect as many customers as DirecTV.
If you don't want to pay up-front for either DVR or HD, get DISH. If you want to save money by doing dual-tuner receivers, get DISH. If you want simple, stable receivers for a few extra dollars and a peace of mind, get DirecTV. If you don't mind receivers or dishes going bad every few months or with the buggy software, get DISH and enjoy the savings.
There you have it, my POV from selling both customers. DirecTV has more reliable receivers and equipment (though the new D10's are causing more problems than the Hughes we carried before), while DISH has some QC problems on some of their parts. I like both but in the end, I got DISH for my home as DirecTV would have cost more upfront. I have a 921 and 2 311's as a Free DISH deal. No way I'd have paid $650 for a HD Tivo even at cost. The 921 was only about $350.