I coated all of my running gear with Black Widow last winter. After about 90 hours of run time this past season, the paint held up well wear-wise. No visible wear on anything, even the prop tips (still had the slight brush marks I hadn't fully polished out). Props were clean to the touch at haulout, the rest had just a hair of slime that wiped off with a bare finger.
However, I did have some adhesion issues. I used the Pettit prop coat zinc stuff as primer. On the shafts and props I got some tiny spots where the paint and primer bubbled off, it seems. But only a few spots here and there. The struts held up fine other than 1 chip in the paint. The leading edges of the rudders lost some paint as well, and I had serious paint bubbling and failure (lost about 40% of the paint) on the trim tabs.
In my case, I don't think it's an electrical issue, as the tabs and rudders had been holding paint fine before I stripped them to do the Black Widow. I'm thinking either I didn't get the surface finish rough enough, or the primer wasn't adhering well enough (the failure spots were right to bare metal, but the rest was still well adhered).
So this year, I'm going to strip the running gear back down to metal, prime it all with Primocon, then coat with Black Widow. We'll see if that holds up better.