Early on there used to be quite a few complaints of regulator/rectifiers causing problems, although this hasn't been brought up much in the past 5 years or so.
A big problem is the two multi connectors sat in the bash plate leading to the reg/rec are not protected from huge amounts of crud from the road.
Although I have nothing to prove it, I think the reg/rec is reliable, what goes wrong is shorts or corrosion in the multi-connector.
Easy fixes are to regularly clean and descale. Probably better to try to seal it up, but beware of trapping moisture in so it cannot escape. Any sealing up has to be really well done.
The most effective fire and forget method is to cut out the multi-connector (one at a time, the wires are virtually all black!) and hot solder them together. a good bit of shrink wrap can ensure these exposed parts remain doing their job unhindered.
The only downside for the soldering option is that it is permanent. I swapped my wiring loom and cursed myself because of the solder but it wasn't hard to undo and there was no corrosion under the shrink wrap after 7 years.