Im in the beta, and can say it's actually really great.
The latency is excellent and really feels native.
The boxes they give you are 3060's and are limited with application control to ony the game you chose to play.
This means no mods, or 3rd party software allowed; not that it's really convenient as it get's destroyed when you end your session.
With some trickery you can escape it's sandbox to a browser, but after the thrill of a speedtest, there just isn't anything to do, if you try execute anything downloaded, it will end your session; which is really solid design on their end to protect their interests and the users from being naughty.
All round I think it's a solid option for folks wanting to avoid the upfront cost of a PC.
The Nvidia app's are great, work well on an iPad and even samsung tv's have the geforce now app.
I believe they use 4:2:2 chroma subsampling rather than 4:4:4, so if you look closely you can probably spot streaming artifacts.
With a decent fibre connection 50mbps+, you'll have a really great time.
I think it's all going to depend on the pricing, here's hoping for R200 / month for the 3060 box, and R400 / month for the 3080 box.
You'll need all your own games, but xbox game pass, steam and epic games can all be signed into, you'll also be able to browse the steam app from within the VM so you can buy / interact with it as you need.
This is not financial advice: If you want to poke around with the steam workshop, i'm pretty sure you could figure out a way to upload your own executables / run your own code in the VM.