4 years and still love it!
I bought my Sonata brand new in August of 2015. It is comfortable and spacious. It handles well in all kinds of weather, even in -40 F temperatures on a trip to northern British Columbia.
Mileage is good on highways... it's not hard to get 30 mpg. City driving is another story. We often get only 18 or 20, and I'm not an aggressive driver.
There are only two things that really bother me: 1) The cabin LED light above the console is way too bright for night driving. I have tried a few different materials to cover it and dim the light a bit. 2) the driver's seat belt quit retracting properly around 65,000 miles, and the dealer told me it wasn't covered by warranty. Now at 105,000 it just about never retracts on its own.
When I replace this car, I'll probably look at the Ioniq, only because I'm a high- mileage driver, and that hybrid has the Sonata beat by a long shot.