To follow-up, I read up on the PW-X2, it looks like it mainly gives more power (less power drop-off, specifically) at high cadence (above 80-90 rpm) compared to the previous Yamaha motor. Also they got more sophisticated with an auto mode that adjusts boost level to account for slope as well as speed, cadance and torque. Where I live they need to account for headwind speed, same with @Alan1115, it sounds like.
Here is one PW-X2 review, sounds like the improvements are aimed at high-performance MTB riders who like high cadence -short cranks. Personally, that's not me, not sure about the OP,
For model year 2020, the Japanese brand introduces the new Yamaha PW-X2 eMTB motor, aiming to set a new performance benchmark. We have all the key information about the new PW-X2 here, our exclusive first ride impressions and more! The new Yamaha PW-X2 motor is based on the same hardware as the...
ebike-mtb.com