That was the main question that I had -- how durable and cost effective were these wheels?

According to this page (p.148) of the "The Railway Purchasing Agent (Jan 1881)" they had a service life of 500,000 miles vs 50,000 miles for cast iron wheels resulting in an operation savings of 3.5 cents per 1,000 miles.

[https://www.google.com/books/edition/Railway_Master_Mechanic...]

Given the rave reviews and obvious cost savings, it makes me wonder why|when they fell out of favor; my naive assumption would be a dramatic improvement in metallurgy?

Disclaimer: statements made using an historical sample size of n=1 ;)