dblkil: Just an addendum I play around with the track editor a bit after my last post.
It's very basic you can only shape up the track, not modifying the objects (foliage, building, scenes etc).
There're some restrictions like how tall a ramp and how tight are the turns, probably so that custom tracks don't break the game.
Not as comprehensive like say, Rollercoaster Tycoon or Trackmania.
Buy it for the game itself, it's worth it.
Thanks for the info and for testing it out! Seems track editors are hard to come by for both modern and earlier games. I've had this in my wishlist for a long time and I'm waiting for a sale on GOG (it wasn't on sale this summer sale) rather than getting the steam version.
Is there a reason to get MR1 or is MR2 a more improved version of it with more of the same?