Like mikeisted, I bought my 2012 S in the middle of last year from a dealer. It had been used as a demo bike and only had 2000 miles on it. Because it was 2 years old the warranty had just expired.
Within my first 100 miles I started getting the power loss glitch, possibly because I was riding it and leaving it out in the rain for the first time. The firmware update and a new BMS board under recall reduced the impact of the power loss but didn't stop it.
After another 3 weeks at Streebike here in the UK and dozens of e-mails to Zero, I have finally conceded to Zero's "more than reasonable" offer (their words; definitely not mine!) to discount the price of the new motor and new MBB board by 25%. I haven't had a positive experience with Zero, despite Aaron Cheatham, Zero's "Director of Customer Experience" <aaron@zeromotorcycles.com> indicating that we would be able to come to an agreeable resolution. The most insulting part is Zero's argument that the bike's previous use as a demo and having been ridden in Canada will reduce its life. Like that justifies it failing at less than 2500 miles!
$2100 later, the only silver lining is that Zero say they have very recently redesigned the 2012 motor. They are providing me with a hybrid motor based on the 2013 design. If they did their job correctly this time, the motor won't fail before its 1 year part warranty is up! At this point, I'm not holding my breath.