Well, I will have to report back my own findings, as no one answered.
The CDT-8 Pro started out sounding very warm and valvey with a distinct prevalence of upper bass/lower mid range.
After 20 hours things cooled a bit, but timing and depth positioning was all over the place, symbols and drums sounding as though they were not part of the same kit.
After 40 hours textures started to show through on strings, there is masses of upper frequency detail but it is all disjointed still.
After 65 hours, this is more like it, fine detail, breathing of orchestra players etc audible. The venue ambiance is present and individual instruments in an orchestra have the right presence level when relating to each other. Electric guitars have that edge to them and deep male vocals have gravel in the voice.
I would say things are still improving. If there are op amps in the unit (probable) then my experience is that these take up to 100hrs to settle in. The last part of the run in doesn't gain much, so at 65 hours I am probably getting 95% or more, of what is available.
This is a very, very good transport, I have an all balanced set up into semi active speakers. I'm using the CDT i2s output into a PS Audio Gain Cell DAC. This DAC has a built in Analogue Pre Amp, that uses their variable gain control, so no attenuating volume pot in the signal path. I run Rod Elliott's active crossover board, using all discrete op amps. This feeds two dual mono Nord class D power amps, that contain Hypex NC500 modules and Nords own discrete input buffers. The set up has a dead silent background and is very revealing.
The speakers are modified Yamaha NS-1000M that use Scanspeak 12" bass. This mod gets F3 from 50Hz down to about 30Hz in my room, F6 25Hz.
The CDT-8 Pro is very natural sounding, in as much as it just gets out of the way, the biggest compliment I can give it, is you don't know its there.
The music has a rich organic sound with no added artefacts and is more analogue sounding than any digital source I have previously had in my set up. Whether the i2s output has anything to do with this, I can't say, but what ever the reason, the sound is superb.