This is my first Mario Kart since the DS, and I'm having a great time. I haven't touched the single player, just online against other players. I was losing every match until I saw that smart steering post, and now I'm doing well. It definitely wasn't letting me do my crazy drifts on the edge of the level, so it had to go. Feels great in handheld and docked modes.
I'm worried about the kart parts. I really hope that I can just use them to balance out preference rather than making a weight class better than others. I beat BoTW before my copy arrived, so I'm mostly playing Link.