If what is contained in that white paper were true, companies like JBL and the rest would have adopted that format.A well designed vented enclosure does not sound slow and flabby like the article is stated.
A transmission line is usually a lower effeciency system. Compression and distortion will be much higher than a properly designed vented or sealed system to attain the same output levels.
That's my 2 cents worth at least!
Ron