Looks like nobody really answers your questions.
The service gets new PS5 games every month (every Extra/Premium PS5 game being added to the service is available). Quality is great, I play some of my games through the cloud rather than installing them on my PS5, such ad The Man Who Erased his Name, quality looks almost native, no real lag issues nor artifacts.
It's a great way to play PS5 games without owning a PS5, the main issue being the game catalog is limited to the Extra/Premium PS5 games (and classic games converted to PS5)