I didn’t check the 2 samples yet, that you mention in your last post. The 2nd one has no metadata available, I don’t know at what ISO the image was shot.
But some thoughts: maybe we expect too much. The Noise Model slider has been introduced in PL6, in DP and DP-XD. Suppose, that the setting NM=0 in DP is identical with DP in PL5. If I compare the results of your 12.800 ISO image processed with the settings DeepPrime, lum40 or lum100 (noise model=0) and DP-XD, lum40 or lum 100 (noise model= -100), then I probably prefer the DP-XD result. (Note: I suppose, that the texture that I see in the DP-XD result in the background actually is present and not an artifact of the processing). It seems, that the Extra Detail that is promised with the introduction of DP-XD is strongly dependent on the Noise Model slider, and that with high ISO images you can’t afford a high setting.
I tried once more with an ISO800 image, and I definitely prefer the DP-XD result (settings for DP and DP-XD: lum 10, NM 0). And the result with NM+100 is even better.
Next question: is the difference between DP and DP-XD large enough to pay the upgrade? I doubt it.