Just thought I'd chime in with my experiences with PS Now last night. I signed up for the 7 day trial, and I played a little of Dead Island: Riptide (never played), and Uncharted 1(I got the platinum trophy for this one, as well as played it a few dozen times,so I'm VERY familiar with how this one should look/feel).
My internet connection is about 40-60mbps wired, and my PS4 is connected to the Internet wired.
Visuals: both games looked incredibly sharp, like they were actually running natively on my television. I'm using my 40" 720p Samsung set, which is in our bedroom. The 40" 1080p set is in the living room, but currently only the PS3's are connected. I plan on getting my wife a PS4 of her own so she can play Dragon Age on her own box, and that one will be in the living room. Point is, on a 720p set, at least, the games looked great. I didn't detect any artifacts or pixel oration during my hour playtime.
Controls/Input lag: I did notice a little bit of input lag while playing Uncharted 1, but in truth, it was incredibly minimal, practically non-existent. Moving around and making jumps and head shots felt good and responsive. I did have to lower the sensitivity for aiming in both games, but that's more of a preference for me. I don't like super fast reticles, but I did play at both default settings, and my adjusted settings to get a feel for the lag.
Overall, I came away incredibly impressed, and I think I'll keep my 3 month subscription that will trigger after the trial ends. There are quite a few games on the current list that I've never played, and would like to.