Train Simulator is a really good program from all reports but it's very European in it's support and fan base.
I bought Trainz actually and tried it too but was super disappointed in the controls, the selection of rolling stock and routes and especially in the poor frame rates. I think on my I7 Hyperthreaded 64 bit system with an NVIDEA Quadro FX 2800FM (96 cores) graphics card at 1920 x 1200 I was down to 7 FPS.

The chug chug chug was too much to bear so I uninstalled it at that point and have never used it again.
Paul of course is right that ground cover and forest do some funny things. But Paul also knows that more and more of us are having trouble with MSTS on Windows so OR is our saving grace at this point allowing us to enjoy the fruits of his labour albeit with a few stray trees here and there and some weirdness in the ground covers. It won't be, as Paul said, until the editor comes out 2 versions from now that anyone will be able to specifically edit routes for OR from OR and see what's going on to fix them specifically for better appearance on OR.
By the way, I discovered that while running OR you can hit the "pause" key, then hit the "8" key for a free roam camera and take your time composing screen shots. And even better still, whether frozen in pause or running, when you hit the "PrtScn" button, OR takes progressive screens shots, labels them with the time and date and stores them in your Library\Pictures\My Pictures\Open Rails folder as PNGs. Nice
I'm busy playing OR in multi player mode again today. Fun!