Have a friend who wants to add a EX HD to his older system. He called Dish and they transferred him to an upper level teck and the teck told him his unit will not work with an EX and if it did he had to buy the ex from Dish he couldn't use the one he purchased elsewhere. He called back and asked for sure which unit does he have(he cant find the number) and they said 625. Is this a good number,as I only see questions about 622s. The second teck told him that he could use his own EX HD,as Dish doesn't sell them,but his receiver is too old to use an EX HD. If this is true,is there any way he can save his recordings on his hardrive,as he would like to update to a 722. Thanks