Thanks for the reply. If I understand it correctly I can replace my 722K with a Hopper with Sling. However to go with a Hopper 3, I have to replace a lot more. Is that correct?
Also what makes the Hopper 3 so much better? All I see is 16 channels vs 3.
Thanks
You can easily replace the 722K with a Hopper
Duo by yourself. Just unhook the cable that comes in from the dish to your separator (or triplexer) on the back of the 722K, and hook that cable directly to the Hopper Duo. If you have two cables coming in from the LNB or switch directly to your 722K (rather than going through a separator or triplexer) then you only need to connect one of those cables to the Hopper Duo.
For a Hopper With Sling, you would need two cables from the LNB or switch, to connect to a Solo Node that enables the three-tuner functionality. Then you would run a single cable from the Solo Node to the Hopper With Sling. Joeys would also be connected through the Solo Node.
For a Hopper 3, at a minimum you would need to either change the LNB on the dish to a Hybrid LNB, or add a DPH42 switch to your existing LNB. Then, if you want to add any Joeys, you would also need a Hybrid Hub. (Hopper Duo also requires a Hybrid Hub to add a Joey, but no other Hybrid equipment would be needed.) Unless you can get Dish to agree to install equipment that you did not purchase directly from them, you would likely have to install all of this yourself, or find someone else to install it for you.
With a Hopper Duo, you really don't lose much functionality compared to a Hopper With Sling, as long as you don't care about the actual Sling part. (Which you currently don't have with your 722K anyway.) Yes, there are only two tuners in the Hopper Duo. (Exactly like the 722K.) However, that second tuner in the Hopper Duo can record the four major networks (ABC, CBS, NBC, and Fox) all at the same time if you subscribe to the satellite-delivered locals. There is no automatic recording of prime time shows, nor is there AutoHop, on the Hopper Duo. However, you don't have those features on your 722K, either. Hopper With Sling has the YouTube apps, while Hopper Duo does not have those apps.
If you are interested in purchasing a Hopper Duo, check the Classifieds section on this site. You may find a much better deal on a used Hopper Duo there than you would find elsewhere.