Mike, I don`t have enough time on the 185 to make that comparison yet
But I think the good points so far are:

1The removal of the Pulse tube to the pump ( this gave fits to some with clearence issues and cut tubing causing lean up line runs)
2The fuel economy is better resulting in much cleaner runs when set correctly.
3The sound (tone is deeper and sweeter sounding under load)
4The bottom end Torque is improved ,and we can run up to 1" bigger diameter props reducing rpm and noise further.
5The weight is nearly the same
6Vibration is less
7The power jump is equal to the jump from the 160 to the 170 with the hyper pistons.
8 overall tuning is easier to set.
9 less smoke than the 175 ( all plays into fuel economy,and cleaner runs)

Although I must say the 175 has been the best 4 Stroke ever produced by YS as far as trouble free and maintenance SO far, I Think the 185 will be equal to that standard.and this motor is another Grand Slam!
Bryan