This track is really hard for me to grind, not only because it's the longest track and because the level design is boring, but because of the random lightning. I think that Eggman and Big are equally fast on this course, but I use Big because he is more fun to use and I think he has the highest skill ceiling.
For me, the only difficult part of the course is hitting the boost panel after the curvy section. You can see that I don't immediately wheelie because I'm trying to hit it.
All full game runs have been retimed to use IGT, and the rules have been updated accordingly to clarify this for future submissions to avoid confusion.
No longer will you need to button mash through menus to save a fraction of a second (in fact, please don't do this as it might result in your race