Fake_frames feature impressed me the most to be honest, but when I saw in reviews what that meant (messed up images and high latency), nothing. Absolutely nothing impresses me with the RTX4090.
Let's look at it objectively - it's the largest chip possible for this application built on the smallest node possible; of course they can cram in many shader processors, thus lifting performance up from so called previous generation. Oh and nvidia copied shader reordering idea from intel cards or whatever, so there's that to lift ray chasing a bit, but that's it. We shall see how the normal cards fare compared to the "previous generation".
It will be a shader_reordering vs. no shader_reordering excrement show at around $1000 a pop prices. The country's in the very best of hands...