They're hydraulic. On mine they were "normal" speed, similar to the turbine, so there's gotta be an adjustment somewhere. I never kept my flap in the Neutral position because then they'd start to droop. Never could find a hydraulic leak - they just did that.
Daryl - have you looked at POH? If I recall correctly, full power, full flap, the damn thing stalls at 39kts! Mine was an absolute STOL ship when you pushed here around. Very Impressive. I miss my 520. It was a great little twin.