I feel like a Mario Kart track can change depending on the game that has it. For instance, there are tracks in MK8D that care so much better than when they were first featured in, say, Mario Kart: Super Circuit on the GBA. I feel like having an SNES track reworked for Switch physics could be a good thing.
So I just did a 50cc race on SNES Mario Circuit 3.
I mean... not bad. Basic, sure, but nothing inherently wrong with it. No jumps and no anti-grav, but there are turns where you can hit max charge on drifting. Plus, the main theme sounds great in the new game.
The Tour tracks are different in the sense that they go through changes the further you get into it. At one point, I was driving one way down the track while the other racers were driving a different direction. It was weird!
But they're still really fun. The structure of the courses is very well done
Out of the 16 new tracks we've gotten so far, two of them, Ninja Hideaway and Sky-High Sundae, are brand new. They're both very good tracks. I really can't wait to try them in multiplayer. If I had to pick a favorite between the two, I would probably say Ninja Hideaway, but they're both very welcome additions to Mario Kart 8 Deluxe.