When I first bought my 2012 S and had a couple of minor issues, Zero came to my home and picked up my bike, took it to the factory and made the repair. Then they did the same thing with the encoder programming upgrade. Now if I have any issues, my dealer takes care of it and if they can't (like when my 2014 S power tank wasn't working), Zero sends a technician to the dealer's service shop and performs corrective work there. Since the power tank problem, I haven't had any issues that needed to be resolved.
My daughter has my old 2012 S and ever since the encoder recall, the bike has run reliably and without any performance issues. It now has about 10K miles on the clock. However, the tail light assembly had to be repaired when the supporting bracket failed and various plastic rivets that hold the plastic together keep falling out, but both of these problems were easily corrected with hand tools, a few hardware store parts and a little time and did not need the assistance of Zero support.