With regards to the direction .....
Since '74 I've ridden the trip west to east (return by bus). However, each time it is with some regret, since I do have fond recollections of my one east to west trip in '73. Something different about starting in Antonito. From the train station the landscape is very deceiving, no obvious mountain range to the west, only low plateaus. Once on the train, your senses are very acute to slight differences in the terrain. This is probably because you haven't been beaten up by the six hour train ride yet. Each rise in elevation is fascinating. The loop around lava tank, the tracks at Big Horn, the Whiplash (wow what construction). The slow vegetation change from sage, to juniper, to pine and aspen.
Just when you get use to the slow rate of change, your find yourself winding along the high shoulders of the rounded mountains that border the Los Pinos River valley. Now you are gliding 400 hundred to 700 hundred feet above the valley floor. Bang! your dead center in the most delightful scenery of the railroad, approximately from Mud Tunnel to a few miles west of Osier. Lean out the window, look at the vistas, feel the mountain breezes, and enjoy. You will be tantalized by the Gorge Region so much that the 3 mile hike from Osier to Toltec Tunnel will be put into the next days agenda. Of course you'll miss the climb to Cumbres, but that is the best reason to make a return trip someday.
By the time you get to Chama you will be tired, but a railfan will soon be re-invigorated by a visit to this second to none rail facility.