EDIT: Here is one from the Economist from last year describing NAV Canada in favourable terms as compared to the FAA.: http://www.economist.com/news/science-and-technology/2170347...
And the Wall Street Journal (paywalled): https://www.wsj.com/articles/u-s-canadian-air-traffic-contro...
And the Financial Post (part of Canada's National Post): http://business.financialpost.com/news/transportation/u-s-lo...