Greg:
They used it on some runs in the 80s when the GW was trying to get something going with a passenger train. I think they were even thinking of a dinner train. Problem is the country where the GW runs is like Kansas (no offense to anyone in Kansas), flat, dry, lots of corn fields (that use to be sugar beet fields). It would be interesting to a rail fan, but the scenery does not even come close to most of the Colorado tourist lines. They tried something like this on a stretch of ex-Rock Island track out of Colorado Springs and it failed too. Why take a train ride through corn fields when you can go to Durango, Chama, Leadville, the Loop, etc.?