The photos on the website are indeed mosaic-ish and heavily compressed, not very pretty to look at. On the other hand it is not often that you can read a hands-on review of impressive hardware like this, and that is perhaps where the strength of this article lies.
However, my impression of the essay/review (besides it being in bold face apparently) was lead away from the technical aspects by the following two , in my view problematic, points.
First, the complaint that "over a period of several months...people I focused on saw me more often than not, before I could get a shot off" and following conclusion that what was needed, was in fact a bigger lens.
I would not deny anyone their personal approach to street photography, but the problem of people noticing might precisely be the length of the "400 Takumar often combined with 1.4 or 2.0 extender"... and getting a bigger lens does not exactly make one blend in better... it would seem that more may be gained from a smoother shooting style, or is this too simple? The comparison to a sniper's rifle by the above poster goes in smoothly with me.
Second, the above cause-and-effect may make the quest for "that magic moment before they realized their picture was being taken" difficult in the writer's view. In fact, in my view it is almost a 1-to-1 relationship, unless that lens is coated with invisibility paint. But the central issue for me here is the assumption that people would have some "magic state" in which they are totally themselves and not aware of their surroundings. If you wait long enough with a shorter lens, observe your surroundings, and move naturally this assumed state of magic does not have to be broken in the first place. edit: Wasn't there a story of how Cartier-Bresson would walk by a scene, put up his camera, press the shutter, and walk away all in one fluent move?
Because of the above two problematic points, I was unable to read the article with an unbiased mind and a comparison to a disease known as "lens lust" and used by people with too much money in their pocket in amateur forums came to mind. If this is unreasonable, I will be happy to accept any corrections in my way of viewing things here.