I also own the JRD unit, and have no issues, mine drops off from 15psi to 14psi but is rock steady from there, i also run a fuel cut defender and have a ces dump pipe, so i dont get any turbo back pressure, for the money of the JRD unit you cant go wrong and a EBC is not worth the money as they also have spiking issues.
As for the spring getting stuck its common with all ball and spring controllers, when winding just slow it down.