transport sound quality of good modern CDPs

Used to be they made big heavy expensive CD transports that improved the sound out of your DAC over a standard CDP transport section. Very few are made anymore, yet there are plenty of good outboard DACs on the market. The better one-box CDPs can often sound as good as redbook allows, yet most seem to use generic off-the-shelf ho-hum transport mechanics with maybe a little tweaking to the servo circuitry. So my question is two-fold:

1) Have the lightweight seemingly modest transports in excellent sounding $2-4K CDPs gotten good enough that their mfgs feel their sound can't be significantly improved by using a near-industrial-grade transport?

2) Would there be a notable sound difference by running the digital output of say a Musical Fidelity A308 CDP into a $5K outboard DAC vs running a Levinson No 37 transport into the same DAC? Or for that matter, a Rega Planet or NAD C541i?