I couldn't imagine a classroom any different from the one he describes in the right hand column. I have a colleague whose students produce projects which are fairly carbon copy. I would argue that indeed a look at projects and their student led evaluations is an indicator. But it does seem to miss out on a real indepth look. I would however, run screaming from a school where all the projects are posted and look identical in presentation, but I'm fairly kneejerk that way.
Rubrics are drudgery and can be real brainwork.
He turns instead to reliability within raters. It is harder to train people to score say writing with rubrics, but I have felt the scores were more accurate if they were at least adjacent. The comment you dredged out about traditional ed. as being less rigorous than what he suggests was quite accurate in my experience as well. His Appendix B was a concrete and welcome example of what classroom learning environments should and shouldn't look like. Kohn of course realizes that the people who want to score schools can't possibly visit every one of them.