[CatDancer]

Your article doesn't list any of the library features that tipped the scale in favor of Arc.

The features of Arc are well described in the Arc tutorial, http://ycombinator.com/arc/tut.txt would you recommend that I include a link to that?

it doesn't stand well under scrutiny ... public technical rationales aught to be a little more than ...

Well, I had posted it to the Arc forum, where people are already familiar with Arc. I expect that your criticism is valid if it had been intended to be a technical article.