The only other failure I've had is that the rear shock wore out prematurely again, replaced just before the end of the two-year warranty. It's clearly under-engineered for me; I'm a big guy, though I'm clearly within the weight capacity of the bike. I've begun searching for aftermarket solutions that may be more robust, but there pretty clearly aren't any. I've contacted Zero about the problem, and they've acknowledged that it is a problem, but they haven't proposed a solution to it yet. I'm at 23,000 miles now, and it seems to last just about 10,000 before losing all damping, so I've got time. It may very well just be a matter of rebuilding with higher-quality seals; since they were replaced under warranty both times I didn't even have a chance to investigate a simple rebuild.
They've also clearly upgraded the entire suspension with the Showa components, but they're not compatible -- much different shock mounts. Whether mine could be machined out to accommodate the Showa unit might be something I have to investigate.
Just to re-iterate, I don't feel like I've got any right to complain about reliability. The shock failures haven't stranded me anywhere; the only failure that did immobilize me was the charger failure. In 23,000 miles, I've paid more for new tires than for repairs or for fuel, so I think my bike's been living up to its promise very well. Considering how new and small of a manufacturer Zero is, I'm pretty impressed with the reliability I've experienced.