To your first question, I would avoid using GameStream on wifi. I've used it with my PC being wired and just my Shield on wifi and the latency was quite noticeable.

As for using a Shield just for media consumption, it is fantastic. I very rarely notice any dropped frames of animation in any apps and it has no problem with moderate bitrate 4K (50-60Mbps, might go higher but that's all I have). I do have the Shield 2017, though, so I do not have 4K upscaling and in theory the performance is a bit worse. If you get a new Shield, you will have an even better experience.

I have two Nvidia shield and only stream TV Netflix Hulu Amazon prime and a few others also while being connected with my laptop working I usually see no lag on the network but I also have a pretty good multi band router.

Don't get much chance to play games but my daughter has a PS 4 and she plays on it while I'm watching Nvidia shield and on my computer and she doesn't see any lag.

I love the Nvidia shield it's fast however you were watching a supported app on the PlayStation it's faster. hell it's got so many extra cores and it's so much more power.

I recommend the shield I only can compare it to the Amazon cube and fire stick and it's way way faster.

Shield TV is the best there is. There's no comparison. If you can afford it, buy it.

I was looking for the Shield Pro the other day and it looks like it is sold out everywhere. Anybody know what's going on there?

I have 2 shields, one in living room, and one in my boys' bedroom. I've used games streaming with both shield and PC on 5ghz wifi, works great. I did have to get a WiFi extender for boys' shield, as it was further away from the router, since I did that it works as good as the one in the living room.

Would recommend a shield to anyone, regardless of the scenario (unless they strictly say it has to be cheaper than $120, then I just tell them good luck).

I would also recommend it, it is still the best package, which is good and kind of sad.
Also: Yes, use ethernet, Wifi is good on the Shield, but even with my Ubiquiti UAP AC PRO it is still about 4-5 ms slower than ethernet. and jitter is a lot worse too.

Five years later it's still the fastest Android Box available.

In the USA there are some other pretty snappy Internet Video Streming only options available. Namely the Verizon Stream TV and the AirTV Mini. The $50 TiVo Stream 4K should be out real soon too with great MIMO Dual Band WiFi.

Not sure how they go with Bluetooth Game Controllers, but PC game streaming would work if using the PC and a Wireless game controller RF dongle attached to the actual PC itself.