So, you wanted someone with experience with the Hopper Duo to chime in. Here I am! I don't want to go off on a rant here...
(This is your warning that this post is the TL,DR version. Get out while you can! You've been warned.)
The Hopper Duo is not as much of a downgrade from other Hoppers as you might expect, considering that Hopper Duo has the 24/7 feature that allows recording from all four major networks (ABC, CBS, NBC, Fox) on a single tuner (if you subscribe to the satellite-delivered locals) just like all other Hoppers. Yes, "24/7" is Dish's actual code name for this feature. Apparently, they couldn't come up with a catchy name like Prime Time Anytime to explain this feature, which is probably why they don't advertise it for the Hopper Duo.
The difference between "24/7" and PTAT is that the Hopper Duo does not support the automatic recording of everything in prime time, nor do you get AutoHop. Therefore, you need to manually set individual timers for each show you want to record, and manually skip commercials. This is the same way this feature works outside of prime time hours on all Hoppers.
Still, with the 24/7 network recording feature and a dual-tuner OTA USB adapter, this means that the Hopper Duo is capable of recording up to seven shows at the same time. All this while allowing you to watch something else previously recorded (or streaming, or On Demand) while your shows record in the background. This is still a huge step-up from any ViP DVR, although it is obviously nowhere near as nice as the Hopper 3.
Now, on to my one major gripe with the Hopper Duo: the lack of apps. Yes, there are some apps included, but nowhere near as many as the Hopper 3 currently supports. Some of the most popular streaming apps (such as YouTube and Amazon Prime) are missing from the Hopper Duo, for example. There are cases where the Wally (a standalone receiver even older than the Hopper Duo) has perfectly functional apps that, on the Hopper Duo, do not work properly or are completely missing. The Dish Music app and Hopper Arcade (when that was still a thing) are examples of that.
Even in a case where the Hopper Duo has an app that the Wally doesn't have (Gallery) it is not that big of a deal. There is a work-around for Wally where the additional Dish Scapes in the Gallery app are available in the regular On Demand section during free previews. I assume it is also that way full-time for people who subscribe to Gallery, although I have never actually subscribed to it in order to check that for myself.
The lack of YouTube on Hopper Duo is a real shame, since Dish actually was working on testing both the regular YouTube app and YouTube Kids app on the Hopper Duo on two separate occasions. I have seen this myself, so I know the Hopper Duo was technically capable of supporting both of those apps just fine at the time. I suppose some changes could have been made to these apps in the meantime that would make them no longer technically compatible with Hopper Duo. However, I choose to believe that it is simply Dish policy keeping them from being added to Hopper Duo, until someone can prove otherwise.
At the time the YouTube apps were removed from testing on Hopper Duo for good, Dish added the Locast app. I guess Dish needed to free up some room in the Hopper Duo in order to add Locast. Yeah, that was a good business decision! Locast was only actually available in seven markets at the time. Locast eventually expanded to a few dozen markets, but now they are completely out of business. Meanwhile, YouTube is still doing just fine nationwide. So, where is the YouTube app for Hopper Duo now?
Hopper Plus would go a long way toward addressing the lack of apps on Hopper Duo. Unfortunately, Hopper Duo is one of the models that will not support the Hopper Plus, at least not right away. So, the receiver that is in the most need of adding more apps is the one that gets the shaft, while the receiver that already has the most apps (Hopper 3) gets even more added. Yeah, that seems fair.
This is similar to how the Hopper Duo does not support the Super Joey, which would add two more satellite tuners. Again, the receiver that is in the most need of additional tuners is the one that cannot get them. Super Joey will not work with Hopper 3 either, but obviously the Hopper 3 does not need any additional tuners in the first place.
I think this lack of features (or only having stripped-down features) is deliberate self-sabotage of the Hopper Duo on Dish's part. They want to force customers to spend more money to get the additional features (even ones that the Hopper Duo can technically support) by upgrading them to a higher model, rather than offering a true lower-cost alternative.
Anyway, for the above reasons, I finally sold off my purchased Hopper Duo receivers, and instead purchased a Hopper 3 last year. So, I am withdrawing from the battlefield, since I no longer have a dog in this particular fight. Thanks for reading my one final rant about the Hopper Duo, and have a nice day everyone!