And the 500s had been hardware retrofitted at extra cost ($200k per?) to not display tape to make them compatible for type rating with the 300s. The FAA required this for a single type but the FAA didn't require them to be a single type. We looked at round dials for 20 years because the company didn't want to have different type ratings way back when they got the 500s. The tape displays aren't just pretty. They are safer because they display the info in a more coherent and intuitive format. As usual the company prioritized cost (single type) over safety. And the beat goes on with no more ground school, train by memo, etc.