The new rails are way easier to turn on ,and don't seem to grab ,just comparing my 8,7 flow to my 8,7 placid ,also my acid more rounded rails .
The older flow is still a great board ,but its when you get the rounded rail in choppier and stepper waves you appreciate the rails ...extra rocker kick might be a bonus too ..as i've nose dived mine many times .old flow is still available on request mike ,like all the older models ,nobody buys acids anymore ...

its board evolution .