After a few months, I realized that I was using it in my 1080p system quite a bit more than in my 4K office setup. The main reason was the lack of 4K compatible apps.
Enter the Roku 4
Luckily, I got aRoku 4 for my birthday and it allowed me to just move the Nvidia to the living room. The Roku is just a much better fit if you have it hooked to a 4K monitor that doesn't have its own apps.
Top ten reasons I prefer the Roku in my office and the Nvidia in my living room:
1. Amazon Prime - with the limited amount of 4K content from each provider, it is nice to have numerous 4K options. Unfortunately, the Nvidia doesn't have an Amazon Prime movies app.
2. UltraFlix - Another 4K source that Nvidia doesn't natively support.
3. Vudu - Rumored to be coming to Nvidia for months, but it is still unavailable.
4. There are other apps (M -Go & Toon Goggles) that support 4K that I am unfamiliar with, but needless to say it is nice to at least have them as options.
5. Optical out - my 4K monitor does not have digital out, but luckily the Roku has digital out, so I can use that output to get 5.1 channel sound. The Nvidia has USB audio out ( other than HDMI), which was good for two channel audio, but had no way ( in my setup) to pull DD5.1.
6. IP Control - the Roku is compatible with the Simple Control app. The Nvidia isn't. This means that it is easier to control the Roku in my office from my living room system with the remote app on my iPhone. The Nvidia can be controlled with an IR blaster. I have a blaster in the living room, but I don't have one in the office.
7. The Roku has a smaller footprint. My office desk is fairly jam packed as it is, so any extra space is appreciated.
8. Included Remote control - the Shield's remote (game controller) is iffy from the couch in my living room (loses connection), but the Roku's remote is rock solid from the same distance. By moving the Nvidia into the living room, it is closer to my couch, but also close enough to get a solid connection in my office. Since the living room receiver feeds both rooms, I can still use the Nvidia in my office ( I got an extra Nvidia controller for Christmas), but it is limited to 1080p. If I had 4K capable receivers in both rooms, I could just keep both of the machines in my living room ( run one HDMI output to the living room TV and the second HDMI into the office though the shared wall), but right now I have to be able to change out the Roku's cables easily ( to change back to 4K) since my receivers are 1080p.
9. Roku is more popular - since Roku is in many more homes, developers are more likely to provide new apps, including 4K apps, to Roku before Nvidia.
10. Roku ongoing support - This is a side project for Nvidia, so there is a question of how much time and effort they will put into updates and pursuing new 4K sources.
This isn't to say that the Roku 4 replaces the Shield. The Shield is better for gaming, the UI feels faster, Google Voice is better than "Roku voice", the SD card slot is useful, the ability to hack it to add features, etc. It just means that I think Roku is currently better for 4K and a better fit for space in my office.