OK this is AWESOME and has a ton of potential! I just think you need to polish off a few things. A friend of mine and I played this together against 30 bots and it was a lot of fun. We have some general criticisms for you:
1) The terrain gets really rough in some places; I think you could smooth it out and take into account the Scorpion's handling to make the drive a little less difficult in a few areas. I love the ramps, though!
2) There are a few areas where the signs are either not quite clear enough at first or aren't properly placed where it confused me and I drove into some unescapable lava. There's one ridge really close to the end where the sign could probably be moved down a bit to make it more obvious that you should go left instead of right. Let me know if you want screenshots of the problem areas I'm talking about.
3) The signs at the end need to be more obvious that it's the end. I thought I was supposed to drive around the stinger turret building or go through the gate, but couldn't and got shot up. Maybe put a big sort of FINISH LINE indicator somewhere for added comedy and clarity.
4) A few places seem to have the lava doing damage above an elevation where you'd expect it to.
5) Behind the end building, there's one bit of terrain where you can fall in and be unable to get back out of, either in a Scorpion or on foot. It's behind the building and thus not likely to be visited, but you still may want to fix that.
6) This is clearly designed for player vs. player. It's cool how bots actually take the course, but as it is now, everyone meets up at that one central location near the start and that's where most of the fighting is. I think you may want to add just a few alternate paths for more potential meetup locations, like one at that ramp, one a little further behind the ramp, and one in the first town area, or something like that. Could add a little variety to the gameplay and make it less likely for there to be huge fragfests and less racing.
7) You might want to add some Warfare-style teleporters to the main bases so that players can quickly reach defensive positions. This could make the race a bit more challenging for players who get ahead of the game, as there would still be potential they would have to face turrets.
8) The Shock Turret is possibly a bit too powerful in the ruined town where it is. I would either reposition it or add some geometry to give it less of a clear line of sight of oncoming cars. If not that, I'd try replacing it with a rocket turret.
9) More huge ****-off ramps, please! I loved that one over the lava, but I was hoping there would be a couple more that required a boost to get over. You could warn players well enough in advance with a sign like "WARNING: BRIDGE OUT AHEAD" or something so that they would have time to save a boost for the ramp.
10) The extra Scorpion garages are nice for weaker players who bang up their vehicles, but one thing you could try is removing those and instead adding lots more Link Gun ammo along the course so people have to take better care of their cars. Maybe only one midpoint garage would be good? Also, you might want to protect the garages from Stinger Turret fire, as there is one where the enemy can shoot at the cars. Human players would be able to blow up the Scorpions before anyone could get there and keep doing it.
11) Maybe you could add some narrow paths meant only for footsoldiers on hoverboards, complete with hoverboard boosters. These could work as shortcuts for those willing to take the risk of trekking on foot or for those who lost their cars to enemy turrets or lava or whatever.
That about does it. Really, the map looks great and runs flawlessly; performance is perfect. We think you could definitely increase the terrain resolution and smooth things out some more without affecting performance, and possibly add some extra routes here and there. Also, if you took out the garages, it could be more like a real race; you only get one car, so either slow down and avoid hazards/damage, or stop to fix it up when you take too much of a beating. Either way, this prevents a mad rush for the finish without taking proper care of your car.
I would absolutely love to see you make a map similar to this but designed for Vipers or Mantas! Hell, maybe you could make it for Vipers AND Mantas; pick your craft and get going! Could work well as an indoor tech/urban map I think.
Great work so far! The concept is solid gold and the execution is already a lot better than I expected. Can't wait for the final!