Although this paper certainly seems legit - while also supporting the general opinion of some (if not many) players -, I would feel more comfortable if this case study would have been conducted by a different institution, because when it comes to science, critical thinking and objectivity are essential.
A (perhaps overly critical?) person might conclude regarding this paper: Scientists from Shanghai found out that the product of a company - which is coincidentely also based in Shanghai - is superior to the product of a major competitor from a different country. OK...
The parameters examined are essential and therefore key parameters, but there are likely other parameters as well as other research methods.
Furthermore, the chances that there are connections of some sorts between DHS and the Shanghai University of Sport are rather high...one has to keep that in mind when "digesting" the results.
That being said, I wonder what japanese, german, swedish, american (or whatever) insitiutions would find out regarding this matter. They might very well come to the same conclusion as the people who released the paper, but still...well, as I said: I would feel more comfortable if it was conducted by another insitution, because then it would be an upgrade in credibilitity, so to speak.
I'm not defending the Nittaku Premium by the way. I like them a lot, yes, as long as they have not become slippery - and they become slippery awfully fast - as was previously explained by
@Der_Echte. This effect is not as pronounced with the newest DHS DJ40+, which is why I currently prefer them (as long as I'm allowed to sneak them in at the club...

).