"Whisper Quiet" or "Dual-Ducted" Air Conditioning - reviews?

I have been seeing lots of newer fifth wheels moving to what are called either "Whisper Quiet" or "Dual-Ducted" Air Conditioning. A Whisper Quiet system is essentially being marketed as the result of a Dual-Ducted AC system.

The difference appears to be that the RETURN air to the AC unit is through a second set of air ducts, compared to the traditional AC units where the return air is directly into the ceiling mounted AC unit. This allows the AC compressor and blower to be mounted more outside of the RV living area reducing the noise somewhat.

Here is Heartland RVs diagrams and explanation of how they do it:
Heartland "Whisper Quiet" details


Here is a picture with a traditional AC unit mounted in the ceiling:



And here is a Dual Ducted system picture (notice the 2 large return vents in the ceiling):


Personally, I "think" the dual-ducted system should be much quieter but I haven't been able to test it out myself yet.

Does anyone have real-world feedback on the benefit of having a "dual-ducted" or "Whisper Quiet" system?

If so, did you notice any noise improvements?

Are there other (good or bad) consequences from the change to a dual-ducted AC system?

Thanks,
Ed