I can't remember what the other RR was, but in one of the books on SP&S motive power, it was said that the crews didn't like their Prairies at speed because they rode hard. But, a number of them went into local/branch service, which I presume to be low-speed affairs. I took that to mean that they were not considered good as main line power for through trains.
I know that the Prairie was used on other roads, and it was a long time before I read about some other RR saying the same thing about them as the SP&S. I have not heard that from any other road.
Kennedy