Actually I found streaming to be just fine.
The experience felt just like playing a console to me.
I bought the whole controller/chromecast package but you don't need it.
You can use a standard bluetooth controller/keyboard/touchscreen whatever and play on anything
Windows PC, Apple, Chromebook, Android, Smart TV
I didn't notice any latency that distracted from the games myself. (shrugs)
It did play smother when I was closer to the router.
I did have it conk out on me a few times and once or twice it felt like the chromecat melted after marathon gaming.
I have the cheapest internet available too.
I usually play in 720p or maybe 1080p.
It claims it can stream up to 4k. (I don't have a 4k TV, and am not sure I want one) pretty sure my internet couldn't handle it anyways.
A youtuber made a video a few months ago testing it out and said it was fine, he pointed out some occasional artifacting.
Said he could tell some latency when playing racing games.
Anyways now there's around a dozen services just like Stadia now.
Amazon Luna just launched in March and looks like a clone with its controller.
Doesn't have nearly as many games though.
The app itself (GUI) especially on the Chromecast sucked.
There's a list of a few most recent games on top and then rowes of four or something of all your games owned below it.
If you have tons of games then then it cant take awhile to scroll through all of them.
I'm sure they are in any sort of order either, maybe recently played or most played.
There's only a few system options and browsing the store is a horrible experience as well.
It can be a pain every month to find your new games.