I read the samething in Turkey and Turkey hunting.
A couple of weeks ago I shot Flight controls thru a Tru-Glo gobble stopper non-ported, and my Carlson ported tube. I use the Carlson all the time.
My pattern was better thru the Carlson. I'm sticking with my Carlson and the Flight controls. During this little test the wads out of each traveled the same distance down range. For what it's worth.