Nothing so far it seems, except for how long it takes to beat them/how many points you're able to get on the different paths. The 3 last missions seem to be always the same either. My opinion goes to that any% would be required to be played in Arcade-Mode and that you're free to choose what path you're going to take out of these 19 paths. Even though one of these will be the fastest in the end that everyone's gonna run. But maybe the path changes because some new skip was found. Or maybe 2 paths are very similar time wise and only differ for a couple seconds. That's one of the reasons why I think we shouldn't have 19 categories for the same ending. IGT should be used, unless it's inaccurate.

Oh and maybe we could use the other paths for races on SRL.

I also did a "run" of a path I thought might be fast and got a sub 44, so runs won't be longer than 44 IGT minutes. You can watch it here: http://bombch.us/B_lg No audio because Elgato acted up. This was just to see how long an any% run might take, how Path 7 looks like and for fun. Would be also cool if we wouldn't put random runs like these on the leaderboards at first.

I would also be for a "All missions" category, there are 20 missions to chose from and the main game does keep track your time you've spent in missions, even if you don't complete them. It would require you to: Use a completely new save file, have to beat every of the 20 missions, beat Andross as the last mission. IGT should be used aswell unless it's inaccurate. I'm not sure about the requirement that Andross has to be the last mission because you do unlock certain events of past missions if you progress through the main game. We'd have to investigate how these events are actually unlocked.

And for 100% I can't say much yet.