We have a 2014 model Volt. It hasn't had a single problem, is fun to drive (excellent torque), and gets terrific overall mileage.
My wife's commute is just over the typical electric range, so it switches over to hybrid mode from electric only mode most weekdays. Even so, we've received 71.4 mpge (181 mpg of gasoline). Only 83% of our miles have been electric only, because we've taken it on trips of up to 2,000 miles where it ran almost the whole way in hybrid mode at 70+ mph. Based on our electric rates and the amount of electricity we've used, I've done the math and found that driving it in electric mode is like paying 63 cents per gallon of gas in a car that gets 40 mpg.
There have been an extremely small number of complete battery replacements reported (zero due to loss of range), and the battery is covered by an 8-yr or 100,000 mile warranty. Occasionally you will hear of somebody who needs a battery interface circuit board replaced (about $300), but the Volt is designed to protect the battery in all situations and only uses about 80% of capacity so the battery is never actually completely discharged. They've been out in the wild now for five years and have surpassed 100,000 in sales. The drivetrain has proven to be so reliable and efficient that GM is now using modified versions of it in several other models, including the new Malibu Hybrid.
Finally, the ultimate test of whether buying a Volt is a smart decision: it is always at or near the top of owner satisfaction scores every year.