I've got the OG model, and it's still the main device hooked up to my TV. All my TV streaming goes through it (mostly Jellyfin these days), and it can stream games no problem via Moonlight.
It's hooked up to a 4k LG TV, and I have no idea about how it does the upscaling, but 720p content looks perfectly fine on it.
Best (worst?) of all... it still gets updates.
The only two complaints about mine is the one set of updates about 5 years ago that killed every connection to my NAS, and that the auto skip function for credits doesn't know if there are scenes after the credits.
But overall, for running it for like 9 years with a cost of less than $200 and essentially zero maintenance, the shield is awesome.
I thought the Shield's claim to fame was it was a certified 4K Android TV device because it could handle it early on?
Yeah I just loved the one where they forced ads on the homescreen. Now I use ProjectIvy