We've had directv since 1996-we have some really old boxes in storage now! Directv has an agreement with Tivo and their DVR is sooooo much better than cable (had one house where we just couldn't get a good signal and had to suffer with cable). We also have three standalone tivo boxes that work with the directv box.
A couple things, the quality of the install can vary widely, from wonderful professionals who wire everything perfectly and don't quit until you have a 100% signal to complete idiots who pull your phone wire from the exterior wall and steal beers from your fridge.
I kid you not; I've had both experiences with the mover's package. So, when you call up to purchase it, tell them that you've heard horror stories about bad installers and you want them to send you the best.
Then, when they show up at your house, make sure they're putting the dish where you want it (one idiot put it smack dab on the middle front of my house!), and that the wires are run how YOU want them, not what's easiest for them.
Follow them around and watch them do everything.
Be demanding, be firm, and if you have to, call Directv when the guy is there and tell them that the guy is:
A. Trying to charge you for a free service (this happened twice)
B. Running wires across your kitchen floor because he's too lazy to go up in the attic (happened once)
C. Has bolted the dish to the front of your house because he doesn't want to be bothered to get up on the ladder (happened twice).
Directv's really, really good about helping you out should you run into problems during your install.
All said, it's definitely worth it.