I know that you cannot mix hopper receivers with other models unless it's a 211. My question is, is there a limit to the amount of hoppers you can have on the account? I now have 4- vip922's, a vip622, and a 211. Can I replace them all with 6 hoppers if I buy them? My biggest issue is my 922's have 4 tuners, my 622 has 3 tuners and the 211 has 2 tuners plus the dvr function. I need to have a bunch of tuners because the family records a lot of tv.