I'm currently playing God of War on PSNow. It's not available in my country, but I selected different region that's ~7000km away from me.
The game is absolutely playable, but obviously, not optimal experience. The connection is stable throughout, no hitches or anything, IQ is very good, only shimmering can be seen in intense action scenes, but it's not noticeable because everything's moving very fast.
The biggest drawback is, obviously, input lag. It's absolutely there, especially in menus where no animation can hide the latency. However, the game was very playable and after 30 mins or so I got used to it and didn't mind at all. I've played a few games locally that had input lag almost as bad.
Overall, I was pleasantly surprised, especially without a server being near me. Excited to try Stadia and XCloud when these come out.