While evaluating this "report" one ought to bear in mind that it was written by Insteon as a marketing tool for Insteon. I noticed that one major emphasis of the article is that "Z-Wave" is a complex, sophisticated system whereas Insteon is simple. This is held forth as an indication of the superiority of Insteon.
The other major track in the article is that Z-Wave uses routing while Insteon uses simulcasting, again with the idea being that this makes Insteon superior. I'd have been shocked if they said otherwise on either count, though I remain unconvinced that their product is superior.
An awful lot of industry giants seem to have decided that Z-Wave is the better choice. That backing, while only indicative but not dispositive of the question of superiority, at least puts Z-Wave in a better position for long-term support.