Rio Grande bummers

K-27s didn't enjoy much of a reputation. The fact that several in the class went through three cylinder blocks of different design attests to some big dissatifaction with them mechanically. They didn't steam all that well, mainly becaiuse a small firebox working against large cylinders. 454 was supposedly the most sluggish of them all, though the soaker 462 was not popular either.

The two C-21s were also sleepy on the steamin' side. 375 was controversial. Some said it was another poor-firing engine, others liked it.
The homemade 490s liked to fall apart and tear up rail. #490 was considered the worst. They fired great and could pull, though.

An old South Park guy told me they hated CB&Q 537. It had a lot of lateral in its two blind drivers and they slipped off the rails on some curves. The crews would just keep going until it rerailed itself on a reverse curve!