Earlier quoted context omitted.
In terms of real time raytracing the RTX will blow the GTXs out of the water... For anything else? Remains to be seen.
This is my big question too. It's pretty standard marketing: if your new product isn't impressively better than the old one on commonly used benchmarks, you invent a new benchmark where your new product is impressively better. I wonder how much of the "look how much better these cards are at ray-tracing!" actually reflects real-world improvements users will see, and how much is there to create a benchmark that shows…
Realtime raytracing wasn't feasible before.