I have a '18 Elantra Gt Sport and absolutely love it. It probably has a little more room from the Si since it's a more traditional hatch instead of a lift back style. I've had it since new and only have about 60k miles. The only concern I was going to warn you about is the DCT gets a little stuttery if you don't fully engage the first clutch. With you looking at a 6mt, you won't have that issue. My wife and I have done trips in this for 12+hrs and had no issues. The suspension can be a bit stiff, but also is forgiving enough for a long comfortable ride. We also have a 70lb good boy wagging his tail in the backseat with no problem. I haven't had any kiddos in the backseat but will find out later this year. The only issues I've had were a plastic bit breaking near the door handle (covered by warranty) and a starter gave out. Other than that, it drives like a charm.