>>Now, I'm a bit confused when dealing with people's preferences
Well, that's the thing here. You can please some of the people some of the time but you can't...well you know. For the record, its not so much that I like smooth, good flowing tracks, I just hate it when I download a track and it's a chore just to stay on the road...lol. No, I mean,
good tracks are made up of a lot of different elements. A person should consider these when making a track, but then go ahead and create what
they prefer. The trick is to know the difference, to be aware that your decisions are being made deliberately, and not unwittingly. A person should be satisfied with their own work first. After all, you have to live with it. If you can get others to like it, then that's bonus points.
The jump over the road that comes a bit after cp#3. To me, it stands out as deliberately contrived since it's the only thing of it's kind. If you're going to play with it, then maybe lowering it would be okay. However, other alternatives would be to make the rise that leads into it more gradual so that it comes across as less a jump than a drop off an edge (you don't need to lose the jump feel, ie don't go one extreme to the other). And no matter which way you go, make it a few squares wider - you can drive around it (to the left the checkpoint is an obstacle, to the right a little bump, but both are faster if you hit it right).
The bridge railings. I didn't really have a problem with this - I just looked at it like speedway barriers. But since it's been talked about, here are a couple ideers. You could use the railings like in
Black Fork or
MC's straight and the making of which
Angus has illustrated well. This would allow the railings but provide see through parts. Maybe a wrought iron look would work. Alternately, you could do something like in alpine's extremely crazy where you raise the edges of the outer ground boxes to narrow the road. This would be similar to what you have but 1) it needn't be as extreme, and 2) add a challenge to the road by forcing attention to the restricted driving area.
Speaking of the road.
I didn't mind ignoring the road between cp 2/3. While it does offer a few second short, it doesn't cut big time off the lap. Also, the angle that you approach cp 3 is affected too. The wider turn the road offers allows you to keep up more speed, I think, and the narrow angle created by going cross country so to speak slows you down a tad. But, if you wanted to give a slight advantage to the road over the cut, all you need to do is set the grass texture to grip depth 20 (or 10) just as you have with the ash base texture. That'll give somebody pause before using the grass but wont slow them up too severely if they do.
My choice has always been to "angle the checkpoint box to match the terrain." but again, that's personal preference.
Checkpoint models. I did notice that it was easy to bump them while passing, but not enough to be a problem. I guess that's why my lap times are still so high. Anyway, after reading everything above, I'd like to suggest you clean up the extra verticies and save them with new names. I think, with a view to the long haul, that this is the better way to go...just eliminate the problem at point zero. And it wouldn't hurt to include the fixes in the fixit pod too, in case somebody grabs them out of straight on. All bases covered.
Lastly, since mal and wk both mention the drivability, then maybe I should say something on it too. Bandwagons can be nice sometime. Anyway, I think the thing is that the wide open track and smooth terrain conspire to make some, let's say, uneventful driving. There is room to pass and room to turn and room for just about anything you want, and there are no "real" obstacles to get in the way, unless of course you grump about checkpoints, lol. But then again, everything you have done is in keeping with the theme, which you don't really want to take away from. Two things come to mind. First, consider playing with the width of the driving area. Nothing grabs a driver's attention like suddenly needing to steer the truck. Secondly, you could use things like were done in godzilla vs bigfoot, where there are cracks in the road that create uneven driving areas. The degree that you use either of these is, of course, up to you.
There's two more cents for you. Now we're up to four.
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- Phineus
). You could make the volcano in the backdrop!! 
I remember a track before called snowy avalanche(by MOP_Zero) and it used animated textures to resemble an avalache. Maybe you could put together a flowing lava combination of textures. 
I either don't have the talent or I'm not reading the instructions right. I'll take a look at Snowy Avalanche and see if it gets my brain functioning again. Oh and if your good at making backdrops (hint hint) I think the best one would be the backdrop I'm using with a volcano in it. 
