I have a 2014 SR with 13,000 miles on it at the moment. I live in San Diego so I've been able to commute on my bike (I have a ~50-mile mostly freeway round-trip commute, and I don't recharge at work) an average of well over 4 days per week. I kept my 528i so I don't have to drive in the rain and can drive long distances or pick up a large batch of groceries when I need to.
In 14 months now, I've been out of action for between fifteen and twenty days total. Five were for the recall (got my motor replaced in five days including shipping, which seems pretty reasonable to me), a few were for a warranty rear shock replacement, five to replace a defective charger (under warranty), a couple to replace both tires and front brake pads (routine maintenance), and the balance were to replace the headlight bracket when the bike wouldn't run because a connector got wet when I washed the bike, and an idiot tow truck driver dropped the bike sideways getting it home so I could work on it.
It's never a good feeling when stuff doesn't run right, and the failure rate on my bike is higher than it should be, but then Zero ain't GM, at least yet, and you have to expect some teething pains still at the point they're at on the growth curve. But even if I didn't have the car as backup, I could easily have rented a vehicle for the time I've been unable to ride, and still come out way ahead on transportation costs....in addition to owning just about the coolest vehicle available today.
Life with my Zero isn't perfect...but it's damn good overall!