content: This is why the post is interesting - real life and theory do not necessarily match, and if you look at the comments after the article, there's a lot of head-scratching because you're absolutely right, and the author of the article agrees with you 100% except after real world testing, the results did not match expectations.  A deeper analysis might reveal if the issue has to do with dropped packets or some other issue at hand, but for whatever reason, the AC routers they tested, did N, better than N-only routers.