The sudden "top to neutral" thing is a bit of a problem. I still have a lovely scar on my knee cap 20 years after the 3speed hub on my BSA "meteor" shifted to neutral whilst i was pedalling home from school. The sudden neutral caused me to slip off the pedals, chip a tooth as my chin landed on the stem then crash on a freshly resurfaced (sealed and chip) road. My one clear memory is of staring at my knee and seeing a white patch surrounded by blood. the white bit was bone.

That said,the SA 3speed hub is a marvel of robust engineering. If they are kept oiled they go forever....

I now have a F&S 2 speed duomatic and like that a lot.