I will be seeing a significant difference in price difference for the first year. One plus is that I will be able to watch in HD on 2 tvs now. With my dual tuner, it only allowed us to watch HD on 1 tv. And we only got that 3 years ago. Never understood why they didn't have HD for both on that dual tuner HD DVR receiver. I don't have a HD tv for the other tv as of yet. But now that I will have 2 HD receivers, I plan to buy another LCD for my bedroom.
The one downside is that we have a standard def dual tuner DVR for my kids. One to my boys and the other to my daughter. With Dtv, I had to pay an extra $99 up front for the boys to have the DVR receiver (they only offer a non DVR receiver for free). Didn't get one for the girl, though. I figure she doesn't really need one at her age anyway.
All in all, I figure I'm going to see around a $40 difference in my monthly bill for the first 10 months. After that it will still be a little less, but only a few dollars. I'm happy with that.