Long flaps help a lot. I have wider cascadia's for the winter and they work great. I have set of skinny PB freddy fenders as well and I replaced the flaps on them with cascadia mudflaps ordered from planet bike, work way better. Really reduces the amount of spray hitting your drivetrain and feet compared to shorties or none.

So there, I recommend the cascadia's, they also are a little more robust than the standard freddy's. Worth the extra $12