Its pretty legit.
Mind you I'm on a gig internet connection and using a 4K iMac.
The lag is really only noticeable when you connect your controller through bluetooth instead of hard wired.
I've won matches of Apex Legends using this service,
you can play competitively but you definitely need a fast connection.
My resolution is the same as if I was running the app natively.
Its only a VM box so I don't see why the resolution would be decreased
I'm sure google is going to knock this out of the park, given that they will have more capacity and resources to pull this off.