Hey riotous, I just tried more GeForce Now. My connection to their data center was 18ms, >50 Mbps, and 0 Frame loss over 5 ghz wifi (ethernet would be best, I know). I was playing GTA 5 with my steam account credentials. The cloud pc had 24 gigs of video ram, and ran the game maxed out at 60 fps while my current rig which is an i5 2500k 16 gigs of ram and a 970 gtx would choke at those settings... It had no discernible input lag using my xbone pad on PC. However, I did feel sluggishness/ input lag playing Team Fortress 2 though with mouse & kb. It was like I was controlling a laggy wireless mouse / analog stick, but I bet it would play fine for single player fps games like Fallout 4 / Cyberpunk 2077.
I must say it does give me pause when about to drop $2500 building a new pc later this year, but I still will. Modding is what will make me stay with local gaming until its a gold standard with streaming platforms. That and my ISP wanting 35 bucks for "Unlimited*", on top of the $100 I already pay for 100Mbps down 6 up.
I did try XCOM 2 and Rimworld and it did download all my subscribed steam workshop mods on the cloud pc, which was nice!
*Meaning they reserve the right to throttle your bandwidth when you use too much of your "unlimited" bandwidth for the month.