Also in the Lathrop book was the story of the 450. It would not steam well unless it had a half-ton of junk in the smokebox, changing the harmonics of the exhaust. This was found out by accident. The crew was waiting for a meet at Doyle, east of Gunnison, when the crew started throwing nuts and such into the stack.
Even the worst of the engines had their stauch friends. Leo Croonenburgs said the RGS 74 would run right if the fireman knew what he was doing.
One of the former Cumbres & Toltec engineers, who I have not seen on this board, did not like the 487s pulling power. D&RGW hogger Andy Payne loved the engine. His said one helper trip stood out as he and fireman Don Gibbs got the engine right out of the shop. It purred like a kitten.