Frame generation is awesome. I've been using it with The Witcher 3 Next Gen and with MSFS. It's a huge performance boost with no negative effects in games like the aforementioned ones. With nVidia Reflex on Ultra there was absolutely no noticeable input lag.
Nice to see it make its way into Cyberpunk. Personally, I will probably be owning a RTX 5090 before I get around to buying the Cyberpunk GOTY on sale but FG should be great for current gen cards in conjunction with those super-psycho RTX settings which bring down even a RTX 4090 to 30fps without FG. We'll see... maybe with a RTX 5090 we won't even need FG for playable fps at psycho settings.