Any geared locomotive is of course speed limited by its gearing. That being said, period sources are full of comments regarding all three types. As a general rule, Heislers were regarded as the fastest of the three. They were prone to some rocking motion while running. Climax locomotives were regarded as the cheapest, slowest, but often considered the strongest pullers. They had a reputation for having a rough ride and I've read more negative comments about this aspect of them than for the other two types. Shay locomotives were often regarded as the best-built and smoothest -riding of the three. Legroom in the cab could be cramped. Crews seemed to like them best on average. Shays had a reputation for having a tendency to bind in curves and tip over if the operator wasn't careful with the throttle.