Well 50x is "greater than", and it still all needs to be proven. Being that they are working on the TDKs and modelling, perhaps the initial run is showing a 20x increase instead -- that's still pretty darn revolutionary for a new technology. If I can run your device/data center at 20x the speed with 4-10x less power than you are using today, that's a great news story.

I'll take a proven 20x gain, over a paper based 50x theoretical limit every day of the week.