There is only one gondola per train; it is the bottom half of an outside frame standard gauge boxcar and even when it appears "packed" there is usually plenty of room. Passengers are also welcome to ride on the platforms at the end of the cars as well.
There are plenty of good viewing places on the train; the problem is not so much finding a good spot, but that there is so much scenery to see! With the wildlife, the changing seasons, and the lava mesa to alpine gorge transition, every trip is different.