I have been running 09 lately on an older 2.16 core duo MacBook Pro. In compatibility mode and windowed I average 30 FPS on my own routes. Of course draw distance is 2500 and detail sliders at normal. Built up areas drop to 20 and more open areas get up to 60. Built in routes like Tidewater are in the teens or less. Older versions of Trainz run super smooth. That is through boot camp.
I tried Crossover's free trial. It looks promising. 09 ran exactly the same with it. Just couldn't get CM to work. Didn't have enough time to fool with it before the trial period ended. Have a look at their forums, some are having success in getting Trainz to run with it.
If not, boot camp works very well. Just beware, Trainz doesn't play well with integrated video. A dedicated video card is best.
Dave.....