Have transports improved for Redbook CD playback?

I think your sort of asking the wrong question. Are there transports better than what you have? Yes for sure. As far as transports improving the pertinent question would be since when? And another pertinent fact CD replay is on the quick decline so not a ton of R&D being done on transports. Did you have a budget in mind?

I don’t know about transports, but the DACs are MUCH better over the past 10 years for Redbook. Simply stunning by comparison. My guess is the clocks or reclocking circuits have improved, but other things like the common use of quad dac chips for a single channel may also be contributing. 

@jond I’m open on budget for a new transport. 

@erik_squires I ordered an Emperical Audio Synchro-Mesh reclocker. It seems as though that is where a significant improvement in signal processing might arise.