I own a Gen3, so the difference was greater than compared with a Gen4.
Test conditions: perfect powdery cold hard-packed snow.
Results: absolutely incredible!
The board rides so smoothly that it dampens all the irregularities on the slope. Using Gen3, I feel the board jerking, with this new model, you have the feeling your are riding on velvet. That feeling is independent of the slope, riding a flat track or a steep one like the Barthelemy, and independent of the speed.
EC style seems easier, the board is incredibly stable, and doesn't deviate once on it's trajectory. It has much less tendency to hop. When carving aggressively on flatter slopes at high speed, it is so stable it feels much more secure.
I find it unbelievable that it is possible to continue to improve a board that has already brought so much to the alpine snowboard practice.
The designers deserve a big praise!
The conclusion is I want one these boards right now. I didn't succeed bribing Patrice to give me his prototype. Next season there will be a used Gen3 selling on the forum…