Only one way to find out for sure John. \:\) Having debated this one at length at other forums I'm of the view that if there is a difference the greater effect comes from artifacts which may be created in the summation not by some concern over whether a gap is created which is inaudible and gets overlapped by the slope. Its all academic because no one can tell if the artifacts are there or not and the difference if it exists is swamped by room acoustics anyway. That's why the author of the article hasn't gotten much replay in the 5 years since it was written. Yet another example of a theoretical concept which does not translate into real world listening applications.

John