Sure, but I think this could be mentioned in the fact box on page 2 along with all the other DS specs.
To me this would bring confidence that this reviewer really knows what he is doing/talking about. As you said, Vade has knowledge about the DS releases and even appreciated the raised performance. PS Audio shouldn’t need to point this out at all, IMO.
Firstly, it is nice to know for comparison/recognition reasons, but also in order to reveal the product’s full potential. You never know, but let’s assume that his statement ‘Even if you’re looking at some higher priced units you should give the DS a listen’ originates from the 6115 upgrade, this in its self is quite significant.
To sum up, I think digital audio is so new (or is it?) that sufficient awareness is not in place, yet (and I have not even started talking about simulated annealing issues).