I have a Sonata plugin. I'm personally are very, very disappointed in the car due to a lack of PTC electric heater. Which means to get cabin heat in the fall, winter, and spring, the car has to run the gas engine. So for short trips, the car is going to go through gallons of gas simply to heat the interior or the vehicle. This is not a very good design in my opinion.
Secondly, the number of cars sold has been very small. This will probably mean that parts will be hard to get at some point.
Thirdly, the car doesn't have a lost of battery capacity warranty. Honda doesn't really have one either outside of Honda saying we will look at capacity loss on a individual bases. So in other words, trust us. Since all electric cars will have some capacity loss, a bigger battery is a huge advantage.
Fourthly, the car has a more normal transmission which adds more complexity to vehicle. Some folks love the transmission, and some will have problems with it.
There are a number of good things about the car. So drive it yourself. Personally for me, I wouldn't buy it due to the lack of a PTC electric heater and the small battery.
See:
http://www.hyundai-forums.com/sonata-all-hybrid-models-yf-lf/