"trained test subjects could distinguish between formats approximately 60% of the time."

Well, 60% correct is not knockin' it out of the park, but the equipment used and the listening conditions are not always ideal in these studies.

Without adequate quality recordings,components and,up including AC isolation and conditioning, it's not worth trying to discern quality. But, if you have high quality components; it's a breeze.
Yes I agree with this that Ac isolation reveals low level details that high res excells at.   
But there are so many other factors it's hard for a study to really ascertain the benefits of higher resolution.