I've had a 24v 913 up and spinning for 7 years now. I had 2 initial problems after about 6 & 9 months and Marlec sorted both FoC.
The regulator packed up after about 5 years and they replaced that with the newer model at cost price.
The new reg copes with V high winds by open circuiting the generator and allowing it to free spin, so no need to lock off blades. Why would anyone want to? Surely, one of the reasons for having it is to keep the batteries up when you are not there.
As I have a 24 and 12v system, my two 12v banks are charged via a relay and a 24/12v converter/charger, all from the 913.
I am very happy with it.