The transports these early $1000 plus Dollar CD players had were without equal today. The main thing is the conversion systems and error correction firmware is better now. The very best today is Tascam
Some of the very early machines had fantastic transports and the reasons for that were many, not the least of which was the tracking and focusing systems were primitive, entirely analogue, and in many cases discrete. They were (and are) extremely time consuming and difficult to set up for reliable operation. Aligning a 1st generation 'battleship' CD player can take half a day to do properly.
Once tracking/focus and disc operations were integrated and then digitised, the tolerances and precision required in the transports was unnecessary.
Longevity was the obvious casualty once the transports were cheapened and the laser diode stripped of its aluminium optical block and high quality glass optics.
Error correction in early TOTL machines was better than anything you see now. Some early Philips and Sony TOTL machines will play right through my CBS wedge test which is over 1.2mm linear data loss. Try that with anything built after 2000. CIRC can theoretically correct over 2mm data loss IIRC.
I have a 'test' disc (a really badly damaged early Japanese pressed demo disc) which will not play on anything except a few early Philips (with CDM0 and CDM1 mechs, the Sony CDP-101 and 4 of my TOTL ES players) Not only will it play, it is quite listenable.
And I am interested, what specifically does Tascam do with CIRC to make it the best available? It is, after all, the error correction system that has been used since the outset. CIRC, coupled with some predictive logic and robust interpolation algorithms has given us 34 years of essentially perfect data recovery from damaged discs.