We have had no problems as of yet.
The Sonata is a wonderful car. The design of the exterior is tremendous. The interior of the GLS has a wonderful feel to it. It is as nice as any Honda I have been in. All the controls are within the drivers reach and easy to use. I did not want to like the car at first and tried to get my wife to look at the Saturn L series as we have owned two Saturns previously. I had, but to dive the car once to fall in love. Provided nothing major breaks I am going to buy another one for me.
I just traded in my 05 Escape for this one.. man what a difference. It rides smoother, so quiet.
The xm is hot. Gas mileage much much better.. and to top it all off, lots of room and comfort.. you can lay back in this thing and still be on your way without drinking up the gas.
I was a truck guy - steered into SUVs, but this car was the turning point.