I bought a new 2013 Sonata due mostly to its price and warranty. I've only had the car for a few weeks and I am still forming an opinion about it.
My favorite features are the Sonata's performance, exterior styling, price, and "indicated" fuel economy. My old car barely gets 17 MPG and my Sonata is still on its first tank of gas. My Sonata has more options than I will ever use. But I doubt that I will continue the XM radio or Blue Link service. I also like the car's safety features.
The Sonata needs a smoother ride and more comfortable seats. Road noise from the rear seems high and the radio's sound quality is poor in comparison to my other cars. The XM radio's sound quality is especially poor. The car's steering is "scary" to say the least. A tiny change in the steering wheel translates in to a huge change in direction. The gas peddle is overly sensitive too. When the car's speedometer indicates 62 MPH, my GPS receiver indicates 58-59 MPH. My other car's speedometer always matched my GPS speed. If the car's indicated speed is too high, the indicated fuel economy is probably high too. I would certainly hope the manufacturer didn't do this on purpose.