This isn’t quite what you asked, but I recently (and accidentally) became convinced of the impact of CD transports and drive technology. This arose by comparing an ancient CD-ROM and a recent DVD drive to modern streaming services:
In brief, the more recent DVD drive was much better than the older CD-ROM but both were notably worse than modern HD streaming files. I interpreted this as a function of both disc defects and player technology limitations. Moving to high-end transports should minimize the processing gap, but nothing can resolve disc defects.
Given the very obvious improvements of modern streaming services, I’m not sure there will be much of a place for transports in the future. I now want to re-rip my rare CDs before they degrade…