I too have been lurking for a long time so will respond to the question of which were good steamers although I do not have definitive answers. Enginemen liked the K37s if they were the fireman and 480s if they were running the engine. The K37s could be fired flat so the fireman could throw a bunch of coal in the firebox then sit down and ride a while. On the other hand, the 480s had an easier throttle and were preferred by the engineers over the 490s. The best 490 seemed to be the 499 according to the "old heads" I have talked to. It had a good throttle and was an honorary 480. The 493 and the 498 were very good. The 492 was OK too. The 497 was an OK loco if it had not been on the Farminton Branch, same with 491. The water on the Farminton branch was hard on the injectors. Of the K36s, a lot depended on the mechanical condition of a particular locomotive at the time. If I had to pick one over the others based on what the old heads talked about, it would be the 481, 483, and 484 but again I say it depended on the condition of the loco at the time. I have heard crews cuss the 488 and the 486, but they always in saying the bad stuff about them added that they were due to have flues replaced ETC. They always liked an engine from the Salida shops that was in good condition. The 470s were well liked locos. I heard one Alamosa fireman comment that he liked to fire them because he did not have to step down so far to throw the coal in the firebox. Each guy had his favorite engines for different reasons. Of the 470s, the 476 was the best one of the three when I worked around them (1970s). Overall it fired the best and it had a Johnson Bar which made it easier to run, in that once you got it in a notch it stayed put. The power reversers tended to drift all by themselves and find their own notch. Of the two engines with power reverses, the 473 was the best engine but the 478 was easier to fire because it took less coal and water.
Regards
Woody Woodward