I just got off the phone with someone in the executive office of Dish, who told me if I call him directly, he will arrange free installation of a 721 or 522 if I buy either one elsewhere. There was a lot of talk about 522 problems, which the guy at Dish says was fixed with software downloads. I do not keep receiver attached to phone line, and plan on using receiver on one TV only. I also have a 501 and 301, which I will continue to use in other rooms. Since I can buy the 522 on Ebay, and the 721 is still available through several Dish dealers . . . and Mark (from Dish) promised me installation for either if I call him direct and avoid CSR . . . which one should I buy??? Any input would really be appreciated!